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Open Sections & Closed Sections Trapezoidal Sections COPRA® RF Software User Manual . General Functions © Copyright by data M Software GmbH © Copyright data M Software GmbH Unlawful reproduction, in any way, of this manual and its contents is strictly prohibited. data M Software GmbH makes no warranty, either expressed or implied, regarding these materials and makes these materials available solely on an "As is" basis. In no event shall data M Software GmbH be liable to anyone for special, collateral, incidental, or consequential damages in connection with the use of the materials provided. The sole liability to data M Software GmbH shall not exceed the purchase price of the materials described herein. Information in the manual is subject to change without notice and does not represent a commitment on the part of the vendor. The software described in this manual is furnished under a license agreement and may be used or copied only in accordance with the terms of the agreement. Copyright© data M Software GmbH All Rights Reserved data M Software GmbH Am Marschallfeld 17 D-83626 Valley/Oberlaindern Germany www.datam.de Table of Contents © Copyright by data M Software GmbH I Table of Contents General Functions 1 1. Shortcuts 1 2. Entity Selection 2 3. COPRA® Memory 2 3.1. COPRA® Database 2 3.2. Computer RAM 3 3.3. The CPM File 3 3.4. Archive Files 4 4. The COPRA® Explorer with CADFinder 5 4.1. CADFinder/The box Project data 5 4.2. Flower 6 4.2.1. Flower data 6 4.2.2. Pass (x) 6 4.3. Rolls 7 4.3.1. Station 7 4.3.2. Axis 7 4.3.3. Roll Data and Attributes 7 COPRA® Basictools 8 1. The COPRA® toolbar 8 1.1. Starting COPRA® 8 1.2. Project Manager – Please do no longer use 8 1.2.1. Dialogue box: Project Manager 9 1.3. The Base Functions toolbar 11 1.3.1. Settings 11 1.3.2. Material Choice 14 1.3.3. Station Attributes 15 1.3.4. Roll numbering 16 1.3.5. COPRA® Zoom on/off! 17 1.3.6. Create Project Slide! 17 1.3.7. Save current Project! 18 1.3.8. Reload current Project! 18 1.3.9. Erase COPRA® Database 18 1.3.10. Erase Screen! 18 1.3.11. Create COPRA® Polyline 19 1.3.12. COPRA® Screen Menu 19 2. The COPRA® Database toolbar 19 2.1. View Flower 19 2.2. Get Pass 19 2.3. Save Pass 20 2.4. Delete Pass(es) 20 Table of Contents II © Copyright by data M Software GmbH 2.5. Append Pass 20 2.6. Insert Pass 20 2.7. Fade-in Profile 21 2.8. Fade in Rolls 21 3. The COPRA® Utils toolbar 21 3.1. COPRA® Copy 21 3.2. COPRA® Paste 21 3.3. COPRA® DB Undo 21 3.4. COPRA® DB Redo 22 3.5. COPRA® Redraw 22 3.6. Entity Information 22 3.7. COPRA®? 22 4. Machine file for bearing seats 22 4.1. Modify 23 4.1.1. Pre-settings for creation of drawing 23 22.214.171.124. Settings Assembly Plan Dimensioning 23 126.96.36.199. Breakdown/Fin Pass 24 188.8.131.52. Intermediate/Idler Pass 24 4.2. Copy 25 4.3. Delete 25 4.4. Identifications 25 4.5. Current Machine 25 5. Convert Database 25 5.1. Action 26 5.2. Reference 27 Open & Closed Sections/Trapezoidal Sections 28 1. Profile design with COPRA® RF SpreadSheet 28 2. Profile Design with COPRA® RF 28 2.1. The Create Profile toolbar 28 2.1.1. Create Sections or add Entities 28 2.1.2. Add Entities to the Beginning 29 2.1.3. Mirror Profile 29 2.1.4. Centre 29 2.1.5. Delete one Entity 29 2.1.6. Delete a Sequence of Entities 29 2.1.7. Delete Current Section 30 2.2. The Profile Utilities toolbar 30 2.2.1. Edit Profile Section 30 2.2.2. Move Profile 35 2.2.3. Rotate Profile 35 2.2.4. Split Entity 35 2.2.5. Join Entities 35 2.2.6. Join All Entities 36 2.2.7. Same Number of Entities for 2 Profiles 36 2.3. The Profil Utils toolbar 36 2.3.1. Write Part of Profile to File 36 2.3.2. Read Part of a Profile from File 36 2.3.3. Write a Sequence of Passes to File 37 2.3.4. Read a Sequence of Passes into Flower 37 2.3.5. Material thickness 38 Table of Contents © Copyright by data M Software GmbH III 3. Profile of AutoCAD 39 4. Strip Width Calculation 41 4.1. Theoretical Basis 42 4.1.1. Bending 42 4.2. Profiling/Roll forming to Shape 46 4.2.1. Calculation of Neutral Line 46 4.3. General Observations 47 4.4. Calculation in Accordance with German Standard DIN 6935 49 4.5. Algorithm according to Proksa 51 4.6. Algorithm in accordance with Bogojawlenskij 55 4.7. Calculation in accordance with VDI guideline 3389 55 4.7.1. Creating a Data Table of Gauge Factors 59 4.8. Calculation according to Oehler 60 4.9. Standard Formula 61 4.10. Table 62 4.11. User 62 5. Punching 63 5.1. The Punching toolbar 63 5.1.1. Insert Single 63 5.1.2. Insert Multiple 63 5.1.3. Delete Single 63 5.1.4. Delete Multiple 64 5.1.5. Delete All 64 5.1.6. Copy 64 5.1.7. Move 64 5.1.8. Property 64 5.1.9. Information 65 6. Statics 66 6.1. Section Characteristics 66 6.2. Static Values 66 6.2.1. Geometrical Moment of Inertia 66 6.2.2. Surface Centre of Gravity 66 6.2.3. Principal Axes 67 6.2.4. Torsion Moment of Inertia 67 6.2.5. Section Modulus 67 6.2.6. Maximum Distance from Edge 67 6.2.7. Radius of Inertia 68 6.2.8. Shear Centre 68 6.2.9. Vaulting Resistance 68 6.2.10. Principal Axes Angle 68 6.3. Abbreviation 68 6.3.1. COPRA® Calculated Values 68 6.3.2. Max. Distance from the Edge 68 6.3.3. Boundary Conditions 69 6.4. Formulas 69 7. Create Unfolding 70 7.1. Unfolding via Table with COPRA® RF SpreadSheet 70 7.2. The Flower toolbar 70 7.2.1. Plane of Unfolding 70 7.2.2. Unfolding 72 7.2.3. Fold 73 7.2.4. Folding with Angle/Radius Calibrating Method 73 7.2.5. Bending Straights 73 Table of Contents IV © Copyright by data M Software GmbH 7.2.6. Splitting Straights for Over-bending Purposes 73 7.2.7. Automatic Unfolding 74 7.2.8. Execute Unfolding 75 7.2.9. Dynamic Flower 75 7.2.10. Dynamic Unfolding 76 7.2.11. Dynamic Folding 76 7.2.12. Plane of Unfolding 76 7.2.13. Symmetrical Profiles 76 7.2.14. Calibrate 76 184.108.40.206. Constant Radius Method 77 220.127.116.11. Constant Length of Neutral Line Method 77 18.104.22.168. Track holding Method 78 22.214.171.124. Angle/Radius Method 78 126.96.36.199. Power Bending Method 79 7.2.15. Reference Point 80 7.3. The Profile Utilities toolbar 81 7.3.1. Edit Profile Section 81 7.3.2. Move Profile 85 7.3.3. Rotate Profile 85 7.3.4. Split Entity 86 7.3.5. Join Entities 86 7.3.6. Join All Entities 86 7.3.7. Same Number of Entities for 2 Profiles 86 7.4. The Profil Utils toolbar 87 7.4.1. Write Part of Profile to File 87 7.4.2. Read Part of a Profile from File 87 7.4.3. Write a Sequence of Passes to File 88 7.4.4. Read a Sequence of Passes into Flower 88 7.4.5. Material Thickness 88 7.5. Adapt Flower 89 8. COPRA® Trapezoidal Section 90 8.1. Manufacturing Problems 90 8.2. Profile Design 91 8.3. Bending Sequence Trapezoid 92 8.3.1. Run a Bending Sequence 93 8.4. Unfolding Flower 94 8.5. Outline: Wire Model 95 8.6. Strip Edge 95 8.7. Tangential Transition 96 General Functions Shortcuts © Copyright by data M Software GmbH 1 General Functions You will find important tips, which you should follow under this sym- bol. Under the star symbol you find useful tips. 1. Shortcuts In the modules Profile, Flower, Rolls and NC Data’s the shortcuts "+", "-", "+-", "++" and "--" are available. If changes are made you will be asked whether the changes should be saved in the last actual pass. Please note that that pass number 1 is the end profile, if numbering with passes is chosen. If numbering with stations is chosen station number 0 or 1 (depending on your settings) is the flat strip. You may chose the numbering in COPRA® Settings – Pass- and Roll-numbering. . (+) The shortcut "+" loads the data of the next higher pass number from the data- base. If the current pass is the last saved in the database, then pass number one will be loaded. (-) The shortcut "-" loads the data of the next lower pass number from the database. If pass number one is the current one, the highest pass number will be loaded. (+-) The shortcut "+-" loads the data of the current pass from the database. So all not yet saved changes in a pass will be reserved. (++) The shortcut "++" loads the last pass / end profile of the flower from the data- base. (--) The shortcut "--" loads the first pass / first station of the flower from the database. General Functions Entity Selection 2 © Copyright by data M Software GmbH 2. Entity Selection Some COPRA® dialogue boxes supply a list of entities for modification purposes. Entities can be highlighted in the list using the crosshairs and then be modified. To modify multiple entities in the same way it is possible to highlight all the entities to be modified in the list. The limits of the, from and to values, are within the filter selection set. If the Use Filter for bend angle and Use Filter for Radius are both se- lected, only those entities will be taken care of when selecting the Select! or Deselect!, which match both the angle and the radius of the filter selection set. 3. COPRA® Memory 3.1. COPRA® Database All data of a project are saved in the COPRA® database on the hard disk of your computer. This is project information, common data and the geometry of sections and rolls of all passes. The database covers the COPRA® work files. The database consists of the following files: • ALLGEM.DB → Project information • PROFIL.DB → Section data of all passes • RAHMEN.DB → intern data • VERWTG.DB → Administration of the passes • WALZEN.DB → Roll data of all passes All database files are saved in the project directory. To modify the data of a pass, they need to be loaded into the computer memory. After the current pass data has been modified, it is written to and updated on, the hard disk database. There are various possibilities to save the data of the current pass to hard disk: • The current pass is saved with the Save DB option. • A new pass is loaded into the computer memory with the Get Show option and the Save current pass is selected. • The Save current pass option is selected when exiting a module. General Functions COPRA® Memory © Copyright by data M Software GmbH 3 3.2. Computer RAM In the computer memory, only the data of one individual pass are loaded. Only the data of one pass can be loaded into the computer memory. This is the current pass. In case of a computer breakdown only the modifications made to the current pass will be lost. Modifications made to a pass are only saved in the computer memory until a Save to database is being executed. The design work made with COPRA® is very much faster if, in the first step, modifications are only made in the computer memory. Exiting AutoCAD without saving the current pass may cause a loss of data that are only available in the computer memory. 3.3. The CPM File When opening a new project from the project directory, a project file with the name "PROJECT".CPM will automatically be created. In this project directory all 5 files of the database with the extension *.DB are saved. The 5 work files *.DB of the database are saved compressed in the project file. This saves a lot of disk space. To have access to the project data the project file has to be uncompressed. The database files will be created when uncompressing a project file. The project file should be used to save the latest design situation. If a project file with the latest design situation is existing, it is possible to do test modifications on the project. If the modifications should be discarded, the original design situation can be reloaded from the project file. If the modifica- tions are OK, the new design situation can be saved in the project file. The information of the current project is saved in the project file. When fin- ishing a project, the data of the last design situation should be saved in the project file. All data concerning the section, the flower or the rolls can be used if later modifications of the project should be necessary. General Functions COPRA® Memory 4 © Copyright by data M Software GmbH 3.4. Archive Files Function: Important design steps should be saved in Archive files An Archive file has the same file format as the Project file. In Archive files the 5 database files *.DB are also saved compressed and therefore cannot be modified directly. Opposite to the one Project file, as many as necessary Archive files may be created. The Archive files should be used to save important steps in the design. It is like a snapshot of the current design situation. Especially after having worked with the modules Profile, Flower and Rolls it makes sense to create an Archive file. Archive files can be very useful if changes need to be made to the project or if a similar section has to be designed later. The project file is always located in the project directory. The project file- name cannot be changed. The location of the Archive files, as well as the Archive file names, are defined by the user. The COPRA® database was changed several times since the first re- lease. Therefore it may happen that an old database would have to be converted first. Archive files of previous releases can always be loaded. Therefore all COPRA® databases should also be saved as Ar- chive files. Before old Archive files are loaded a new project should be created with the Project Manager. General Functions The COPRA® Explorer with CADFinder © Copyright by data M Software GmbH 5 4. The COPRA® Explorer with CADFinder Function: Quick navigation during design The COPRA® Explorer allows a quick navigation during design and provides a clearly-structured overview of the existing projects. With the help of files it is pos- sible to page between the individual stations and to determine their profile and roll data. Radii, angles and neutral line can be checked quickly. Furthermore, you can select another option by clicking the mouse, e.g. a different pass number. The pass number incl. the required data will then be automatically displayed as the current pass. COPRA® Explorer can be switched on in the toolbar COPRA® Ex- plorer. The COPRA® Explorer is divided into the main options Flower, Project, Rolls and CADFinder. 4.1. CADFinder/The box Project data All data concerning your COPRA® project are displayed in this box. It can be opened via the button “Projects” in Explorer. If you click the current project with right mouse key opens a window. Click on Properties (at the bottom of the box) to open the dialogue Project Properties . You may see and change the name of your project under Project name. Below the Project name is the Project path displayed. Click the button in order to change the Project path. Next are the items Project comment and Document no.-prefix listed. A click on the button Attribute opens the dialogue Project attributes. You may define general Project attributes such as Company or Profile Number further you may modify COPRA® Project attributes as Sheet Thickness. Confirm with Accept for saving changes. What are the features of this solution? COPRA® CADFinder is a document management system that allows also to or- ganise any files independent from a defined file structure on a storage device. To do so the user creates a nested project structure. The documents can then be assigned to a project in this structure via a document number. The organisation of the documents and the assignment to the physical file path is done by a data base server (e.g. MS SQL Server or an alternative data base with SQL and ODBC sup- port for the multi user version or the MSDE data base in a single user environ- ment). Furthermore user defined attributes can be linked with projects and documents. This ensures a fast retrieving of documents via specific search functions. These attributes in the COPRA® version of CAD-Finder may also be used to complete the title block information in an AutoCAD template. General Functions The COPRA® Explorer with CADFinder 6 © Copyright by data M Software GmbH Also a structured view of projects (project manager) and belonging documents as any number of flexible working catalogues are available for displaying different search results. From here the individual documents can be opened, modified, completed with new attributes, copied and moved very easy and comfortable. The design of the structured view is similar to the Microsoft Windows-Explorer in order to guarantee an intuitive working in a well known environment. A revision control and workflow system is also available for the individual docu- ments. So an older version of a document may be – if desired – saved before modifying in order to have access to previous releases of this document. The his- tory of a file may be saved. The link to the respective project is maintained. So for a document multiple work situations may be saved. The workflow system recog- nizes if a user works on a document and sets the workflow status to "Modifica- tion". In that case any other user may only view the document. When the modifica- tions have been completed the status is set back and the document may be modi- fied by another user. Any number of workflow situations maybe defined by the user. Please refer to the COPRA® RF CADFinder manual for a detailed explanation as well as further information. 4.2. Flower By pressing the button "Flower" appears a list with all passes . 4.2.1. Flower data The flower data box gives you information about the number of elements, outside and inside length of the profile, the length of the centre and neutral line - as well as the value oft strip width. 4.2.2. Pass (x) All passes of the design are listed under Flower. Double click on a pass opens the pass automatically in model view. If you click on the + sign of any station a further list with all elements the profile consists of in the selected pass is displayed. You will get detailed information about the arcs and straight entities the profile consists of if you double click on any element. Arcs: Double clicking on an arc element opens a small box giving information about the neutral line, radii and angle. Lines: Double clicking on a line element opens a small box giving information about the length and the start angle of the straight element. General Functions The COPRA® Explorer with CADFinder © Copyright by data M Software GmbH 7 4.3. Rolls By click on "Rollers" are all Stations, their axes and rolls listed in a box. The button station attributes appears if you select a station and click it with right mouse key. Please refer to Station attributes for further information about station attributes. 4.3.1. Station By double click on a station or by clicking on the + sign, all side, top and bottom axes are listed. 4.3.2. Axis By click on Axis top/bottom/left or right opens a list with all existing rolls. The start and endpoint coordinates of the axis are listed. 4.3.3. Roll Data and Attributes By click on any listed roll appears a list showing the following parameters under roll data: • Roll name • Maximum width • Maximum diameter • Number of entities • Roll type • Weight By click on any listed roll appears under attributes a list showing all available at- tributes like: • Material • Roll bore • Keyway • Roll type top • Roll type bottom • Combination roll • Stamping number • Stamping groove width • Stamping groove depth • Inner diameter • Bearing • Roll number • Roll type COPRA® Basictools The COPRA® toolbar 8 © Copyright by data M Software GmbH COPRA® Basictools 1. The COPRA® toolbar In the COPRA® toolbar the following functions are involved: The icons containing a small black triangle in the lower right corner can be expanded with a click of the left mouse key so that additional information will be available. 1.1. Starting COPRA® Function: Initialise the COPRA® Roll form Software, or flip back to the last, active screen menu page. During initialisation of COPRA®, the system checks whether the required settings are available. For example, all layers required by COPRA® will be created auto- matically. If the AutoCAD commands of the Screen menu are used during design- ing, it will always be possible to return to the last active screen menu. This has to be the first command after AutoCAD has been loaded or a new draw- ing has been created. The last actual project is loaded automatically. 1.2. Project Manager – Please do no longer use In previous COPRA® version was this function used to create an manage projects. But now COPRA®´s latest function, the COPRA® RF CADFinder may be used for that – see COPRA® RF CADFinder manual. The old COPRA® project manager will no longer be available in the next upcoming COPRA® version. . If a project is set current in COPRA® CADFinder it will also be the current one in project manager and the other way round. Function: Create new, display or update existing projects The COPRA® Project Manager is a tool for easy project administration. All pro- jects ever created with the Project Manager will appear in a project list. One directory may contain one project only. COPRA® Basictools The COPRA® toolbar © Copyright by data M Software GmbH 9 1.2.1. Dialogue box: Project Manager Last current: Shows the current project and its path. Selected: Shows the selected project and its path. Project Mainfolder: Shows the selected main directory. An additional main directory for projects can be created. COPRA® Setting files and prototype drawings should always be set. More: It can be used to reload projects, which have been removed from the project list. If selected, a file dialogue box for project files will be opened. Project files do have the extension .CPM. A double click on the filename or highlighting it and pressing OK, brings this project back into the project list. Sort Projects: The project list can be sorted in alphabetical, chronological order or in groups. New: A new project can be created when selecting this button. If the directory of the pro- ject path selected does not yet exist the user has to confirm the creation of the directory. The project path defines the directory where the COPRA® database and its related files will be saved. If the directory was created, the Material’s dialogue box comes up and the coil material used has to be selected. It can be selected, either from the list box or, if a proper material is not yet available, be created by the user with the help of Create. The selected material is the default for all techni- cal calculations like Spring-back and Deformation Technology. data M Software does not guarantee that the material properties shipped with COPRA® are correct as the natural deviations of the coil material may be quite high. After confirmation of the material, additional project information can be entered. This information is optional and may be left blank. COPRA® Basictools The COPRA® toolbar 10 © Copyright by data M Software GmbH Save: Compresses and saves the current design data of the COPRA® database to the project file. When exiting the modules Profile, Flower or Rolls, the project file may be updated automatically by appropriate selection. This function can also be used outside the Project Manager by selecting the Save current Project, option from the pull-down menu. Modify: Project name and project directory can be modified. Copy: Copies an existing project to another directory, which can be selected. Remove: Removes the highlighted project name from the project list. The project data it- self are not removed from the hard disk. A project that has been removed from the project list can be reloaded by using the <more...> button (see <more...>). Info: Information about the highlighted project will be displayed and can be changed if necessary. In the headline of the box selected Project name, Project path, Pro- ject file and Material are shown. The additional information shown can be modi- fied and customised. The material Thickness entered is the one used when de- signing a new section. Customer, Product, Drawing Number, Design Date, De- signer and Comment can be entered optionally. Material: Shows the coil material used for the highlighted project. COPRA® Basictools The COPRA® toolbar © Copyright by data M Software GmbH 11 1.3. The Base Functions toolbar Function: Lists all basic functions of COPRA®. See the following descriptions: 1.3.1. Settings Function: Change the default settings of COPRA® Language: The desired language can be selected in the list box. Languages are connected with the unit (mm) except English (US), which is connected with the unit (inch). Centre of Profile: Displays the section’s centre line. Split Lines in Profile: If toggle is set, split lines between arcs and lines will be shown. Automatic Zoom: If selected, a ZOOM EXTENTS and ZOOM <FACTOR>x is done after every modification. The factor may be set to values between 0.5 and 1.0. If case the fac- tor is set to 1.0 the ZOOM <FACTOR> option will not be executed. Automatic redraw: If selected, an automatic redraw is done when loading a new module. The screen is updated with the current section and/or rolls. The current drawing entities will be erased depending on the updating screen setting in the bottom of this dialogue box. Fade out Plane of Unfolding: If this feature is active, the plane of unfolding will be faded out. Fade in next Section: If selected, the next section saved in the COPRA® database is also being dis- played on the screen. COPRA® Basictools The COPRA® toolbar 12 © Copyright by data M Software GmbH Fade in previous Section: If selected, the previous section saved in the COPRA® database is also being dis- played on the screen. Pass and Roll Numbers: Gives access to all options regarding pass or roll designations. By selecting the Fade in spacer dimensions, option the widths and diameters of the space rings will be faded in. Please refer to chapter Rollnumbering in COPRA® Rolldesign & Rolltechnol- ogy manual, too. Numbering of the different Stations: The numbering with station provides with further options, like separate numbering with station types. Use COPRA® Numbering: The standard COPRA® numbering with passes or stations will be used. All continuing: If your stations should be numbered continuously select the button next to All continuing. The resp. stations separated: If you would like to have a separate numbering for each station type enable the checkbox The resp. stations separated, please. This means that the station types will have an own numbering within their group e.g. Turk head 1, Turk head 2 and so on. Please refer to the in following explained point “Rollnumbering”, too. You have got the possibility to create individual roll numbers. Idlerstations: Enable the toggle Idlerstations if you would like to have a separate numbering for the intermediate stations in addition to All continuing or The resp. stations separated. In this case the idler stations will be as such identifiable and their numbering will eg. be 1-2 . Attach stationtype to profilenumber: Enable the toggle Attach stationtype to profilenumber in order to make the sta- tion type always visible. Thereby the chosen station type (eg. calibration idler sta- tion) will be attached to the profile number when updating screen. COPRA® Basictools The COPRA® toolbar © Copyright by data M Software GmbH 13 Layer Control: Allows modification of all COPRA® layers according to his/her requirements. COPRA® Paths: Provides an overview of all paths used by COPRA® for the current project. Names can be modified according to your requirements. Technology: Determines the decimal signs used during export. COPRA® Options: Provides the option to fade in dialogue boxes for the selection of functions. Fur- thermore, the settings for automatic background backups can be defined. Up to 30 archive files can be backed up, i.e. the 31st file will overwrite the first file etc. Contours as Polylines: If selected, all section and roll contours are drawn as polylines. Clear only COPRA® Layers when updating Screen: If selected, all drawing entities placed on COPRA® layers will be erased when a COPRA® Redraw (C Redraw) or any other updating of the screen is being made, e.g. when using the command Get&Show. If not selected, all drawing entities will be erased when a COPRA® Redraw (C Re- draw) or any other refreshing of the screen is being made, e.g. when using the command Get&Show. This option is very useful when e.g. designing the rolls. For the construction lines a layer of its own can be created. If selected, all construction lines will still be visible after the COPRA® Redraw or Get&Show command has been executed. A typical example is to connect the endpoints of the roll axis with a construction line and use this to create the necessary offset lines to get e.g. even spacer ring dimensions. Clear also COPRA® help layers when updating screen: Deletes all drawn lines on COPRA® layers including the help layer during a re- draw. Automatic redraw when changing project: A redraw will be done automatically when enabling this option and changing into another project and the project will be displayed. If there is actually no data in this project the screen will not change. It is recommendable to enable this toggle. COPRA® Basictools The COPRA® toolbar 14 © Copyright by data M Software GmbH Delete X-References: COPRA® works with X-references when creating assembly plans and/ or when defining individual roll- and station-attributes. It is recommendable to enable this toggle because then the external AutoCAD drawings will be only loaded as indi- vidual roll- or station-attributes when you browse between passes. If an X- reference is saved to network another user may have changed it, so enabling this toggle guarantees that you have always the latest version loaded on screen. Fur- ther you do not have to delete the X-references from the assembly plans manually if you enable this toggle. The dialog box roll information: Show info in Rolls: It is possible to show raw diameter, weight, sequential number for top/bottom rolls, sequential number for side rolls, material and rolls type in the rolls. Alignment: Show the info on the left, right or center position. Description: The roll info described above can be set on none, as prefix or as suffix. 1.3.2. Material Choice Function: Select the material you want to use You may choose a material in a dialogue box, further you may edit material or create a new one and its properties. In the past this could only be done via the Project Manager. COPRA® Basictools The COPRA® toolbar © Copyright by data M Software GmbH 15 1.3.3. Station Attributes Function: Station types can be individually named For each station can be defined which station type it is, e.g., a driven station, side rolls or a welding station or a drawing die and so on. COPRA® takes automatically the station types from tube mill map layout eg. turk heads if a flower design exists. This needs to be taken into account when working with the COPRA® Module M3 (Automatic tubemill map. The listed station types can not be modified if there is data in tube mill map de- fined. If there is no data in tubemill map COPRA® shows you in the dialogue box Station Attributes a hint: There is no data available in tube mill map. The single stations of your design are listed in a table. In order to link any specific attribute click it with left mouse key, please. At the very left of the table is the Sta- tion numbering with COPRA® displayed, on the right next to it the numbering with machine. Station type: You may choose between the attributes main, idler, Turk head, welding, drawing die, lineal and strip guide. Inserted station: If you have later inserted a station - mark the check box Inserted station , please. Then already existing roll numbers will not be changed. The roll number of the later inserted station will be marked with an A. If you want you may adapt these roll numbers via the individual roll attributes. Station sub type: Depending on the chosen station type are additional attributes as pre bending, or calibration available that may be linked to the station. Station: You may define the corresponding number that the station has got on machine here. COPRA® Basictools The COPRA® toolbar 16 © Copyright by data M Software GmbH 1.3.4. Roll numbering Function: Individual roll numbering global for all or for single projects You may define an own roll numbering for your company here. The settings are either valid for all projects or for the current one – depending on your set- tings. A dialogue opens if you click the icon Roll numbering. *ATTENTION* – Please take care whether main- or idler station is chosen (see left side on top of the box). Depending on your choice either the numbering for the main or the idler stations may be defined. The column Selection: Please select here which information you want to add to your individual roll num- ber. Furthermore the option „Delimiters“ is available. You may add e.g. a hyphen between two chosen information in roll numbering. The column Format: Depending on your needs you may add the information complete or as short cut. E.g. drawing number (complete) or DNo. (abbreviated). Æ see also „Abbrevia- tions“ Selected elements: Your selection is displayed here. The line Example at the bottom of the dialogue gives you a preview on how your roll number will look like later. If you need to delete an element from list mark it, please (e.g. Pass number| Ara- bic number) and click this symbol , the symbol is available between the Format and Selected elements column. Click this symbol for deleting all available elements at once the symbol is available between the Format and Selected elements column. For changing the sequence of two chosen elements in top direction you may use this symbol: .The symbol is available between the Format and Selected ele- ments column. If you want to change the sequence in bottom direction you may use this symbol . The symbol is available between the Format and Selected elements column. COPRA® Basictools The COPRA® toolbar © Copyright by data M Software GmbH 17 Short cuts: You may adapt short cuts to your needs using this function. Just click the respec- tive button and a dialogue listing all available short cuts will open. User defined text: By right mouse key click in the column "Format" you may enter a user defined text if you have chosen this option. The information may then be linked to your roll number. It can be linked to roll number if you mark it and press this button . The user defined text may be deleted in the column "Format" by pressing the "Delete" key. ATTENTION when deleting user defined text! If user defined text is deleted from "Format" column it automatically disappears at the right site in the column "Selected elements". Set as Default: The user defined roll number will be used global, for all projects. Set for Project: The user defined roll number will be used for the current project. Numbering of later inserted stations: Please refer to station attributes (point 1.3.2). 1.3.5. COPRA® Zoom on/off! Function: Switches the automatic COPRA® Zoom on or off 1.3.6. Create Project Slide! Function: Exchange automatically created project slide by customised one After the Strip Width Calculation a project slide is automatically being created showing the final section in the preview of the COPRA® Project Manager. With the Create Project Slide function this project slide can be replaced by a user defined one. The content of the screen is independent of any restrictions. It may be the flower, a 3D wire-frame model or even a roll form simulation picture including the rolls. In case it should not be possible to create a project slide, check whether the project name contains a dot. COPRA® Basictools The COPRA® toolbar 18 © Copyright by data M Software GmbH 1.3.7. Save current Project! Function: Save the design data of the current project All design data of the current project can be saved in a project file. Project files have the extension CPM (COPRA® Project Manager). The contents are the same as in Archive files. Opposite to the Archive module the user does not have to enter a filename. The filename is put together automatically from the project name. The Project file should not be used to replace the Archive files! With the Archive files a history of the design process can be created. In a Project file only the last design situation is being saved! The Project file is only an additional option to save the design data. When exiting the modules Profile, Flower or Rolls the Project file can be updated by crossing the respective toggle. 1.3.8. Reload current Project! Function: Load the design data from the Project file into the current project The content of the latest saved Project file is loaded into the COPRA® database. An existing database will be overwritten. 1.3.9. Erase COPRA® Database Function: Erase the COPRA® database files from hard disk The design data of the current project are saved in the COPRA® database files. These database files are work files that should be saved as an Archive or Project file. Sometimes it is necessary to have more than one flower in a project. In this case the COPRA® database files can be erased from hard disk and a new section can be designed. Before the COPRA® database files are being erased their con- tent can be saved in the Project file. If the design data are not saved in the Project file, an additional user confirmation is necessary. 1.3.10. Erase Screen! Function: The content of the screen is erased depending on the Delete options setting If the Clear only COPRA® layers when updating screen is selected, then all drawing information placed on COPRA® layers will be erased. The names of the COPRA® layers are set in the Settings. If the switch is set to all active layers, all drawing information will be erased. COPRA® Basictools The COPRA® Database toolbar © Copyright by data M Software GmbH 19 1.3.11. Create COPRA® Polyline Function: Design of the outside, inside or centre section contour as a polyline The final section of roll formed profiles is very often dimensioned by its contour in- tersection points. When using the standard design possibilities of a CAD system this can be a lot of work. The contour needs to be designed with the help of con- struction lines and then has to be redrawn. 1.3.12. COPRA® Screen Menu Function: Loading the COPRA® Screen Menu In contrast to the OEM standalone version, this function is currently still available in AutoCAD. 2. The COPRA® Database toolbar The COPRA® database toolbar includes the following functions: 2.1. View Flower Function: Display flower of the current project This function is an easy way to display the flower of the current project. It is avail- able at any time and shows all passes saved in the COPRA® database. With the Selection of passes option the passes to be displayed can be selected. 2.2. Get Pass Function: Load a new pass from the COPRA® database and save the actual one Before a new pass will be load from database the actual pass can be saved by this function. A dialogue box with all necessary information will be displayed. COPRA® Basictools The COPRA® Database toolbar 20 © Copyright by data M Software GmbH 2.3. Save Pass Function: Save the current pass in the database The Save DB function saves the module specific data of a pass in the COPRA® database. 2.4. Delete Pass(es) Function: Delete a selection of passes from the database The number of passes deleted will reduce the number of passes. The pass num- bers following the deleted ones will be reduced by the number of passes deleted. If rolls are already available, it is for example, possible to delete the tools only. The actual pass number can only be deleted if it was selected. 2.5. Append Pass Function: Append the current pass to the database The number of passes is increased by one. Example: The number of passes saved in the database is 5. The current pass number 3 is appended to the database. The new number of passes is 6 and pass number 6 will be the current one. The contents of pass number 3 and 6 are identical. 2.6. Insert Pass Function: Insert the current pass into the database The Insert pass function will insert the data of the current pass as a new pass in the COPRA® database. The number of passes is increased by one. Example: The number of passes is 5. The current pass number 4 is inserted as pass num- ber 2 in the database. The new number of passes is 6. The new current pass is 2 and is identical to pass number 4. The pass numbers 3 to 5 are moved one posi- tion upwards. See also station attributes for retraining of already existing roll numbers. COPRA® Basictools The COPRA® Utils toolbar © Copyright by data M Software GmbH 21 2.7. Fade-in Profile Function: Fade-in a selected section Allows to fade-in any section from the database. The current pass will thereby be maintained. 2.8. Fade in Rolls Function: Display rolls for a station The rolls for the section can be faded in for any station. 3. The COPRA® Utils toolbar 3.1. COPRA® Copy Function: Copy rolls or sections Rolls or sections have not to be designed anew. Instead, existing rolls or sections can be copied. 3.2. COPRA® Paste Function: Insert copied rolls or sections The copied roll or the copied section can be inserted in any pass. Rolls can be inserted at any position, for example, top rolls can be used as left or right rolls or as bottom rolls. However, you have to choose the respective COPRA® module at first. 3.3. COPRA® DB Undo Function: Reset commands This function is similar to the "Undo" in AutoCAD. Up to 5 steps can be reset pro- vided that the data was not saved beforehand. COPRA® Basictools Machine file for bearing seats 22 © Copyright by data M Software GmbH 3.4. COPRA® DB Redo Function: Reactivate changes This function allows you to reactivate the last 5 steps provided that the data was not saved beforehand. 3.5. COPRA® Redraw Function: Redraw drawing 3.6. Entity Information Function: Opens a dialogue box with the entity data of a previously selected entity All data associated with an entity can be checked and loaded in a dialogue box. The roll data can be displayed on screen with function key F2 (Test Window). 3.7. COPRA®? Function: Opens the Online Help. The language depends on what was selected under Settings If selected the Online Help will be loaded. The language thereby depends on what was set under Settings. 4. Machine file for bearing seats The relation of the rolls with the machine axes is defined in machine files. These machine files are used in the following modules: • Single Roll dimension • Automatic contour dimensioning • Assembly plan • Dimensioned assembly plan The selection of the machine and modifications of the bearing seats are possible after selecting the Machine option in the main dialogue boxes of those modules. If a machine is set as the current one in one module then this machine is also the current one in other modules. Verify that the settings are not contradictory. For example, the diame- ter of bore must not exceed the inner diameter of stamping groove for roll numbers (Settings for drawing generation). COPRA® Basictools Machine file for bearing seats © Copyright by data M Software GmbH 23 After selecting the Machine, option the Machine data dialogue box is loaded: Machine: All existing machine files are listed here. In order to set the current machine or to modify one, it has to be highlighted in the list. 4.1. Modify The settings of the machine picked in the machine list can be modified. 4.1.1. Pre-settings for creation of drawing After selecting the Modify..., the Settings dialogue box will be opened, in which the values for the borehole chamfer and stamping groove are defined. Fig. 1 Bore for pass number The inner ∅ of the stamping groove has to be greater or equal to the ∅ of the borehole plus twice the chamfer of the borehole. The ∅ of bore for (T/B) can be found in the Breakdown/Fin Pass. The ∅ of bore for (L/R) can be found in the Intermediate/Idler Pass. 188.8.131.52. Settings Assembly Plan Dimensioning Illus. 2 Settings Assembly Plan Dimensioning COPRA® Basictools Machine file for bearing seats 24 © Copyright by data M Software GmbH 184.108.40.206. Breakdown/Fin Pass Here, the details for the boreholes of the top and bottom rolls can be set. These are the values for the borehole details of top and bottom rolls. The inner ∅ of stamping groove (T/B) must be greater or equal to the ∅ of the borehole in the driven passes plus twice the borehole cham- fer. Illus. 3 Borehole details of the driven passes A: ∅ of bore B: ∅ of undercut C: Supporting width (2x) D: Fillet of undercut x: Depth of keyway y: Width of keyway 220.127.116.11. Intermediate/Idler Pass These are the values of the side roll borehole details. Illus. 4 Choose the machine for single roll dimensioning A: ∅ of bearing B: ∅ of borehole C: Depth of bearing set D: Fillet of bearing set COPRA® Basictools Convert Database © Copyright by data M Software GmbH 25 The inner ∅ of the stamping groove (L/R) must be greater or equal to the ∅ of the borehole in the intermediate passes plus twice the bore- hole chamfer. 4.2. Copy The data of the machine highlighted in list are copied to a new machine. The name of the new machine has to match the file format. 4.3. Delete The machine highlighted in the list will be removed from the list. The correspon- ding machine file is deleted. 4.4. Identifications The name of the machine has to match the file format. Only 8 characters are al- lowed. In the identification a detailed description of the machine is possible. 4.5. Current Machine Displays the designation of the current machine. Load of COPRA® Set: Loads the plant data from the COPRA® Set file. Save to COPRA® Set: Copies the machine data to the COPRA® Set directory. 5. Convert Database Function: Modify elements of construction It can additionally convert axes or rolls for example, via a dialogue box. Current: Shows the actual pass. Existing Profiles: Provides information about the existing number of profiles. Axes: Displays the number of axes. COPRA® Basictools Convert Database 26 © Copyright by data M Software GmbH Selection: This opens the Selection of Stations, dialogue box. The number of existing pro- files and axes is displayed. By Max select, the selection of single, multiple or all passes for a defined number of stations are possible. Tool: By Tool, it is possible to choose between top, bottom, left or right roll. Later the selection will be modified. Objects: By activating this toggle the profile will be modified later. Tool: Axes and rolls can be enabled for modifying here. 5.1. Action Offers the following options: • Mirror horizontal • Mirror vertical • Move • Convert Depending on selected action the under objects chosen elements can be modified respectively the action. The different Actions: Mirror horizontal: The profile, axes and rolls can be mirrored horizontal. The action can be done by point of unfolding, plane of unfolding or free point. Mirror vertical: The profile, axes and rolls can be mirrored vertical. The unfolding point, plane of unfolding or free point, can do this. Move: The profile, axes and rolls can be moved. A vector of P1-P2 can be used. The input of the x and y co-ordinates can be done by their values or by the selection of the points by crosshairs. For selecting by crosshairs, use the buttons ->P1 and - >P2. COPRA® Basictools Convert Database © Copyright by data M Software GmbH 27 Convert: By entering a convert factor, the profile, axes and rolls can be enlarged or made smaller by any value. Furthermore, conversion elements from mm to can be made. 5.2. Reference Here is the reference point for the selected action, thus, different reference points are offered. Refer to the next point for a detailed description. The different References: Unfolding Point: The unfolding point is used as the actions basic point. Unfolding Plane: The unfolding plane is the actions basis. Free Point P1: By defining the x and y co-ordinates any point can be selected as the actions ba- sic point. Vector P1-P2: Two points that define the basis of the action can be selected with are two possi- bilities: 1. By P1 (x1) (y1) to define the co-ordinates of the first point, and P2 (x2) (y2) to define the co-ordinates of the second point. 2. Or click at the buttons ->P1 and ->P2. Then the points can be selected by crosshairs. The co-ordinates of the selected points are automatically taken into the dialogue box. Convert Factor: By entering a convert factor, objects can be made larger or smaller, or be con- verted from mm to inches. Open & Closed Sections/Trapezoidal Sections Profile design with COPRA® RF SpreadSheet 28 © Copyright by data M Software GmbH Open & Closed Sections/Trapezoidal Sections 1. Profile design with COPRA® RF SpreadSheet Please refer to the COPRA® RF SpreadSheet user manual for further information. Profile design an unfolding can easily be done in a table using COPRA® RF SpreadSheet. 2. Profile Design with COPRA® RF Function: Create a section with the help of macros This feature allows creating sections on the basis of entered parameters. By se- lecting this icon, three toolbars are opened which will be described below. 2.1. The Create Profile toolbar 2.1.1. Create Sections or add Entities Function: New sections or entities can be added to the existing end of the section After selection, a dialogue box with the respective section macros is opened. Next: Jumps to the next page with section macros. Previous: Jumps to the previous selection. After selecting a section, a dialogue box is opened. Here, the section’s dimensions can be entered with the help of parameters. OK and new Entity: Allows adding another entity to the end of the profile. As a section is existing, an additional page with macros is provided. OK and Section: Creates the selected section. Open & Closed Sections/Trapezoidal Sections Profile Design with COPRA® RF © Copyright by data M Software GmbH 29 When recalling the function, another entity can be added to the end of the section, i.e. at the right end. At the highest entity number, COPRA® numbers the entities from left to right. 2.1.2. Add Entities to the Beginning Function: New entities can be added to the beginning of the section If selected, the same dialogue boxes as with the previous command are available. The new entities will be automatically added to entity number 1. COPRA® num- bers the entities from left to right. 2.1.3. Mirror Profile Function: Mirrors a section This is a useful function for symmetrical sections. All entities will be mirrored. The mirror line is the material thickness displayed at entity no.1 (the beginning of the section) or at the last entity (the end of the section). All entities are mirrored in- stantaneously. Entities of the same type will automatically be joined if chaining is not set to off. If the valid number of entities is exceeded, a warning is shown in the status line. To create e.g. trapezoidal sections, the Mirror option can be used several times. Using the Mirror option a second time will cause all existing entities to be mirrored. 2.1.4. Centre Function: Moves the centre of gravity of a section to the point 0,0 If a section was moved to another location or rotated by using the function, the centre of gravity can be moved back to the point 0.0. 2.1.5. Delete one Entity Function: Remove one entity from the section 2.1.6. Delete a Sequence of Entities Function: Remove a sequence of entities from the section A sequence of entities may be deleted by picking the first and last entity of the sequence. All entities between the picked ones including these will be removed. The remaining entities will automatically be chained again. Open & Closed Sections/Trapezoidal Sections Profile Design with COPRA® RF 30 © Copyright by data M Software GmbH 2.1.7. Delete Current Section Function: Deletes the current section data from memory Entering the Del Curr, function will remove all entity data from memory. As a re- sult you will get a blank screen. This function does not affect the content of the COPRA® database. The shortcut +- allows resetting the changes. Another possi- bility to reset the changes offers the COPRA®DB Undo, function from the COPRA® Utils toolbar. 2.2. The Profile Utilities toolbar 2.2.1. Edit Profile Section Function: Modify dimensions and geometry’s of the section Normally, it is not necessary to modify a section within a flower. This can be done with the standard COPRA® functions. There are only a few cases where function is required. This function allows modifying the calculated length of the neutral line. Be careful with this function as it may give rise to problems. Pass Data: Supplies information about the current flower • Number of passes saved in the data base • Current pass number to be modified • Number of entities in the current section • Material thickness Flower Data: Provides a list of data for all sections within a flower. Open & Closed Sections/Trapezoidal Sections Profile Design with COPRA® RF © Copyright by data M Software GmbH 31 Strip Width: Supplies information about changes of the originally calculated strip width • Original (old) strip width left of the section forming point • Original (old) strip width right of the section forming point • Current strip width left of the section forming point • Current strip width right of the section forming point • Difference between original and current strip width left of the section form- ing point • Difference between original and current strip width right of the section form- ing point • The differences between the strip widths are provided for verification of the changes. Listbox: If selection with the crosshairs highlights an entity, its geometry data are trans- ferred to the edit boxes at the bottom of the window. The values can be modified. Selecting the OK button will make the changes permanent. The entities at the sec- tion forming point (FP) are marked with an asterisk. Radio Button S: Enabled by COPRA®, if only a straight entity in the list is highlighted. A straight en- tity can be changed into an arc entity by selecting B, and the previous data of the straight are saved. If the arc entity is converted back to a straight, the previous data will be restored. Radio Button B: Enabled by COPRA®, if only an arc entity in the list is highlighted. An arc entity can be changed into a straight entity by selecting S, and the previous data of the arc are saved. If the straight entity is converted back to an arc, the previous data will be restored. Bend Angle: The angle of all entities selected in the list is set to the pre-set value. Depending on the selected procedure, the radii and lengths of the entities will be adjusted or a length compensation is applied. This function is especially helpful if, for exam- ple, not the inner radius but the outer radius is used as a basis. Inside Radius: The inner radius of all entities selected in the list is set to the pre-set value. De- pending on the selected procedure, the angles and length of the entities are ad- justed or a length compensation is applied. Open & Closed Sections/Trapezoidal Sections Profile Design with COPRA® RF 32 © Copyright by data M Software GmbH Contour Radius: The contour radius of all entities selected in the list is set to the pre-set value. De- pending on the selected method the angles and lengths of the entities are ad- justed or a length compensation is applied. Length: The length of the neutral line of all entities selected in the list is set to the pre-set value. Depending on the selected procedure the angles and radii of the entities are adjusted or a length compensation is applied. % New: The percentage of the neutral line with regard to the entire original strip width of all entities selected in the list is set to the pre-set value. The lengths of the neutral line are recalculated. Depending on the selected procedure, the angles and radii of the entities are adjusted or a length compensation is applied. For a description of how to select entities refer to General Information. Profile Entity: Here the number of entities in a section can be changed. In combination with the function, dispense length compensation to selection, it is also possible to separate entities. Add: If only one entity is highlighted in the list, it can be copied by using the, Add! op- tion. The new entity will be inserted after the selected entity. If the copied entity is a straight it can be converted to an arc if A is selected. If the copied entity is an arc it may be converted to a straight. The entity data of the new entity are similar to those of the copied entity. Strip width differs by the length of the copied entity. Remove: All highlighted entities will be removed from the list. Modification Procedures: The different procedures have different effects on the section when changing an- gle, radius or length of an entity. Several types of length compensations can be applied. Open & Closed Sections/Trapezoidal Sections Profile Design with COPRA® RF © Copyright by data M Software GmbH 33 Free: This procedure is equal to the COPRA® calibration method Angle/Radii. Change Angle Radius Length Length compensation Angle Unchanged Is adjusted None Radius unchanged Is adjusted None Length Option: Adjust Option: Adjust None Constant Length/Adjust: This procedure is equal to the COPRA® calibration method Angle/Radii. Change Angle Radius Length Length compensation Angle Unchanged Is adjusted None Radius unchanged Is adjusted None Length Option: Adjust Option: Adjust None Compensation with Straights only: This procedure is equal to the COPRA® calibration method Constant Radius. Length compensation is done with straight entities only. If an adjacent entity of the modified entity is not a straight entity, a new straight entity will be created auto- matically. Change Angle Radius Length Length compensation Angle Unchanged Is adjusted With straights only Radius Unchanged Is adjusted With straights only Length Option: Adjust Option: Adjust With straights only Compensation in Adjacent Entities: This procedure is equal to the COPRA® calibration method Tube Profiling. Length compensation is done with the adjacent entities of the modified entity, no matter whether the adjacent entities are straight or arc entities. Change Angle Radius Length Length compensation Angle Unchanged Is adjusted Adjacent entities Radius Unchanged Is adjusted Adjacent entities Length Option: Adjust Option: Adjust Adjacent entities Open & Closed Sections/Trapezoidal Sections Profile Design with COPRA® RF 34 © Copyright by data M Software GmbH Length Compensation: If the selected procedure is based on direct length compensation, it can be de- fined how the lengths are to be distributed at the right or left of the modified entity. Outside: Outside is the entity next to the modified entity, which is further away from the point of unfolding and closer to the end of the section or, in case of closed sec- tions, is closer to the welding point. Inside: Inside is the entity next to the modified entity, which is closer to the point of un- folding and further away from the end of the profile or, in case of closed sections, is further away to the welding point. Adjust: If changing the length of an arc or if an arc is used as a length compensation en- tity, either the radius or the angle can be adjusted to the new length. Angle: If required, the angle of an arc entity is adjusted to the new length. Radius: If required, the radius of an arc entity is adjusted to the new length. Length Difference: After user-defined editing of the section data, a difference between the original strip width and the new strip width may occur. This difference can be distributed to the entities selected in the list. Even: The difference is divided by the number of selected entities. The resulting value is added to each entity. Percentage: The difference is distributed as a percentage of the length of the entity. A longer entity gets a higher percentage of the total difference and vice versa. Open & Closed Sections/Trapezoidal Sections Profile Design with COPRA® RF © Copyright by data M Software GmbH 35 2.2.2. Move Profile Function: Move section This function allows moving a selection of sections by defining reference and tar- get points. The sections to be moved are displayed in the same colour. Optionally, additional sections can be displayed which will be listed in a different colour. The changes will be automatically saved to the database. If only one section was moved, it could be saved optionally. 2.2.3. Rotate Profile Function: Rotate section This function allows rotating a section as desired by selecting reference points. The sections to be rotated are displayed in the same colour. Optionally, additional sections can be displayed which are listed in a different colour. The changes are automatically saved to the database. If only one section was moved, it could be saved optionally. 2.2.4. Split Entity Function: Split one entity into two parts Sometime it may be necessary to insert an entity where it cannot be done be- cause of an existing entity. In this case the Split entity function can be used to break an entity. The entity to be split has to be picked with the crosshairs. The entity data will be displayed and the entity selection has to be confirmed. In case of a straight the length to the break point has to be entered, in case of an arc the including angle has to be entered. If the break position is valid, the entity will be split in the position defined and the new section will be displayed. 2.2.5. Join Entities Function: Join split entities If selected, two adjacent equal entities can be joined. To do so, pick the entities with the crosshairs. All entities between, which have the same geometrical values, will be automatically joined. In case of arcs, the inner radii have to be equal. Open & Closed Sections/Trapezoidal Sections Profile Design with COPRA® RF 36 © Copyright by data M Software GmbH 2.2.6. Join All Entities Function: Join separate entities If selected, all adjacent equal entities are joined within the section. In case of arcs, the inner radii have to be equal. 2.2.7. Same Number of Entities for 2 Profiles Function: Adjust number of entities of two sections The number of entities of the current pass and a second pass is adjusted. In the occurring dialogue box the second pass has to be selected respectively. 2.3. The Profil Utils toolbar 2.3.1. Write Part of Profile to File Function: Writes a part of a profile for copying purposes to hard disk In some types of sections there are repeated shapes. To avoid a new design of these shapes they can be written to file with the Write PP option and copied with the Read PP option. A typical example would be stiffing ribs in a trapezoidal section. Simply pick the first and last entity of the entities to be copied and enter a filename describing that part. The entity data are written to file and are ready to be copied. 2.3.2. Read Part of a Profile from File Function: Reads a part of a profile from hard disk and inserts it in the current section Each part of a profile written to hard disk can be inserted into the current section with various options. After entering the filename these options are listed in the status line: Option 1: A - insert Part of Profile at the Beginning of the Section Entering the option A causes the part of profile to be added to the beginning of the section. The beginning of the section is at entity no. 1. The entity picked first when writing the part of profile will be added to entity no. 1 as the first one. Open & Closed Sections/Trapezoidal Sections Profile Design with COPRA® RF © Copyright by data M Software GmbH 37 Option 2: E - insert Part of Profile at the End of the Section Entering the option E causes the part of profile to be added to the end of the sec- tion. The end of the section is at the entity with the highest number. The entity picked first when writing the part of profile will be added to that entity as the first one. Option 3: G - insert Part of Profile at a Location picked by Crosshairs Entering the option G causes the part of profile to be added at a position picked by crosshairs. The part of profile will be added before the entity picked by the cross- hairs. The entity picked first when writing the part of profile will be added to that entity as the first one. Option 4: N - insert Part of Profile at a Location defined by an Entity Number Entering the option N causes the part of profile to be added at a position defined by an entity number. The part of profile will be added before the entity number entered. The entity picked first when writing the part of profile will be added to that entity as the first one. 2.3.3. Write a Sequence of Passes to File Function: Write flower to file This function allows saving a flower or part of a flower to a file. 2.3.4. Read a Sequence of Passes into Flower Function: Read flower from file This function allows reading a flower or part of a flower from a file. Open & Closed Sections/Trapezoidal Sections Profile Design with COPRA® RF 38 © Copyright by data M Software GmbH 2.3.5. Material thickness Function: Change material thickness subsequently This function allows to subsequently change the sheet thickness for a complete flower. In the occurring dialogue box you can choose between several methods. After having selected a method, a slide provides a preview of how sheet thickness will change. Select: Select the passes, whose material thickness is to be changed. Plate Thickness old: Information on the old material thickness. Plate Thickness new: Dialogue field for the new sheet thickness value. Datum Line: Defines the reference line for the modification of sheet thickness. Iternal Radius constantly: The inner radius of the section remains constant. Outer Radius constanty: The outer radius of the section remains constant. Outer Contour constantly: The outer contour of the section remains constant. Centre Line constantly: The centre line of the section remains constant. Iternal Contour constantly: The inner contour of the section remains constant. Open & Closed Sections/Trapezoidal Sections Profile of AutoCAD © Copyright by data M Software GmbH 39 3. Profile of AutoCAD Function: Creating a profile by AutoCAD polyline The first step when designing a new roll set is the definition of the final section shape. This can either be done with the COPRA® Profile Module or by designing the section with the help of the CAD system. The handling is very easy. The final shape of the section is designed and drawn with CAD functions. For the conver- sion of the shape from a CAD drawing to a COPRA® section the CAD Profile Module has to be loaded and the contour polyline has to be picked with the crosshairs. In terms of AutoCAD, the design of the section has to fulfil the follow- ing conditions: Conditions: • COPRA® has to be initialised • Polyline from a contour or centre line of the profile must be on the screen • The contour has to be drawn as a polyline • Only inside, outside or centre line contour are necessary for the conversion • If the section is designed with material thickness, COPRA® will cancel the conversion. • The intersection points between arcs and lines must be tangent • The inside radius of the section may not be smaller than 0 during the con- version One of the following Options can be selected: Erase Database: The COPRA® database in the current project path will be removed. The number of sections and passes will be zero. A completely new section can be created. Continue: The COPRA® database in the current project path will not be removed. After the conversion of the contour the new contour may be added to the existing section. Cancel: Exits the CAD Profile module. No data will be removed and no conversion is done. After having identified the polyline, a dialogue box appears allowing you to define the settings for section conversion. Material Thickness : The material thickness for the profile can be entered. Open & Closed Sections/Trapezoidal Sections Profile of AutoCAD 40 © Copyright by data M Software GmbH Centre Line: The centre line is the reference for sheet thickness. Contour Line: The contour line is the reference for sheet thickness. Centre of Gravity in 0.0: If toggle is crossed, the centre of gravity of the section will be moved to the point 0.0 after the conversion of the polyline. If there is already a section saved in the COPRA® database, which has not been removed when loading the program, a dialogue box comes up offering various op- tions. Append: The converted section will be appended to the database. If one pass was existing, the new section will be saved as pass no. 2. Overwrite: The current pass, which is pass 1, will be overwritten with the converted contour. Insert: The converted section can be inserted in the COPRA® database. The respective pass number has to be user-defined. The definition can be done in an extra dia- logue box. No: The converted section will not be saved in the COPRA® database. Open & Closed Sections/Trapezoidal Sections Strip Width Calculation © Copyright by data M Software GmbH 41 4. Strip Width Calculation Function: Calculation of theoretical strip width The strip width calculation takes into account the stretching of the material during the forming process. The inside radius of the material will be compressed and the outside radius will be stretched. The neutral line of the material moves towards the inside of the radius during being bent. This causes the length of the geometric centre line to be different from the actual strip width. After having selected the Strip Width function, a dialogue box appears which will be described below. Window: The dialogue box appears, showing a list of all elements. Including, entity no., bend angle, the inside radius, the ratio inner radius/material thickness Ri/s0, the length of the geometric centre line, the length of the calculated neutral line, the calculation method used for a bend, a correction factor being dependent on the calculation method and the difference between centre line and neutral line deltaB. Calculation Method: Allows selecting the method for strip width calculation. Factor: Enter the factor for defining the position of the neutral line. Bend Selection: The options Select, Deselect, Inverse, Filter and Crosshairs allow selecting several arc entities to which the respective calculation methods can be assigned. Calculation Methods: Shows the selected formula or the value from the used table. Section Data: Shows the current data of the section as well as the calculated strip width. Results: The calculated strip width can be saved to a file. The name of the file can be se- lected independently. The file is copied to the Project Directory, Info directory. Open & Closed Sections/Trapezoidal Sections Strip Width Calculation 42 © Copyright by data M Software GmbH 4.1. Theoretical Basis 4.1.1. Bending Bending is a process of cold forming which industrial engineering often applies. Leaving aside edge deformation, the process of bending is limited to a 2D reflec- tion, which allows a ratio of unbent length b, and material thickness t, of more than 5. Thus, for the major part of all bending applications, we can use this simplifica- tion. Due to the elasticity of the material, the actually given bending angle of a finished piece is inferior to the originally bent angle. The importance of the spring-back de- pends on the amount of residual elastic stress before relief. Fig. 5 Stress and strain condition with bent parts of different curvature a : Stress value at yielding point b : Stress value in plastic zone I : Major bending angle; here we only have residual elastic strain. II : Sharply bent metal; here we have besides residual elastic stress tensions in the plastic zone accounting for the major share. Hardly bent sheet metal with a much higher bending radius r, compared to its thickness s, will therefore show a considerable tendency to spring-back into its original position. The higher the ratio ri/s0, the higher the share of residual elastic stress will be. This means that a square-edged curvature has a minor tendency to spring back compared to metal with a significant bending radius. The spring-back which first of all depends on the ratio of bending radius rI, and material thickness s0, will in addition be influenced by the hardness and the mate- rial micro-structure, however it is not influenced by the load period. Open & Closed Sections/Trapezoidal Sections Strip Width Calculation © Copyright by data M Software GmbH 43 For an exact determination of the spring-back, the gauge factor k has been intro- duced; k can be determined by tests. The spring-back ratio K is the ratio of bend- ing angle after spring-back and bending angle before spring-back. K r s r s = + ⋅ + ⋅ = 1 2 2 1 0 5 0 5 , , α α The spring-back angle ρ therefore is: 2 2 1 1 1 α α α ρ ⋅ − = − = K Fig. 6 Spring-back diagram to determinate the value K K : Spring-back relation r1 : Inner bending radius r2 : Inner bending radius after spring-back s : Sheet thickness α2 : Bending angle after spring-back α1 : Set bending angle during the bending process ρ : Spring-back angle Exact values regarding the spring-back behaviour are indispensable if tool design depends on the bending angle, e.g. in case of positive locking bending to shape. During the forming of edged profiles, the spring-back can be compensated by a deeper lowering of the bending rail with a greater side-angle of the bending de- vice. The process of bending causes a shift of the material towards the bending zone. Due to the compressive stress in the inner zone of the curvature, the material is upset and the layers of material will become thicker. In the external zone the ma- terial will be lengthened due to tensile stress and the layers will accordingly be- come thinner. Open & Closed Sections/Trapezoidal Sections Strip Width Calculation 44 © Copyright by data M Software GmbH Fig. 7 Sheaf of lines in an arc of circle The curvature can be subdivided in two zones in which only tensile stress or com- pressive stress occurs. A third zone has to be introduced in which the material is first upset and after- wards stretched again. A limit elongation fibre has been defined as delimitation. This is a fibre where no more alterations due to stretch will occur. At the beginning of the bending process, it is identical to the median fibre and moves during the bending process towards the inner side passing the whole range of the final inter- mediate zone. The fibre, which at the end of the bending process has the same length as before shaping, is the so-called neutral line. Fig. 8 Total elongation of individual layers depending on the edge elongation ea Open & Closed Sections/Trapezoidal Sections Strip Width Calculation © Copyright by data M Software GmbH 45 Fig. 9 Bending radii shown at a shaped sheet metal ra: outside radius rmo: radius of the original centre fibre rm: radius of the centre fibre ru: radius of the neutral line rg: radius of the limit elongation fibre ri: inner radius The non-lengthened fibre does not coincide with the centre fibre of the curvature. This is due to the change in sheet thickness in the bending zone. The curves of tensile and compressive yield stress are usually not the same for one material and the influence of lateral strain should not be underestimated. The thicker is the sheet and the smaller is the bending radius the more differs the position of the neutral line from the centre fibre. The micro-graph section of a square-edged aluminium sheet shows the actual course of the fibre. Fig. 10 Micro-graph of Al 99 h Because of elongation the external fibre is subject to a smoothing of the curvature so that in the centre of the curvature the external radius of curvature will be supe- rior to the one of the lateral zones of curvature. Due to compressive stress in the interior of the curvature, the margin texture might break down so that one cannot classify it as a useful internal radius of curvature. Besides, the illustration shows that because of the material shifts the fibres do no longer follow concentric circles. Open & Closed Sections/Trapezoidal Sections Strip Width Calculation 46 © Copyright by data M Software GmbH During the bending of thick sheets with small bending radii, those edge deforma- tions occur frequently. Because of the pressure the material on the inside is even subject to lateral yielding. The fibres on the outside, however, are lengthened, which causes a weakening of the sheet; it not only decreases the original thick- ness but also the original width in the external zones. 4.2. Profiling/Roll forming to Shape As for shaping, the roll forming or profiling technique is quite similar to the bending process. Due to its continuous process, however, not only the desired changes in shape appear but also undesired longitudinal deformations, which influence the shaping behaviour unfavourably. In calculating the position of the neutral line those longitudinal deformations are disregarded. Exact calculation of the coil stock width is required in order to guarantee stability of dimension within given tolerance limits of a profile to be designed. There are different methods to determine longitudinal modifications in the curva- ture zones. Those methods often use different physical mathematical approaches. 4.2.1. Calculation of Neutral Line Introduction In order to take alterations appearing within the curvature zone during the bending process into account one starts with a neutral line, which is neither lengthened nor upset by the bending process. In unbent condition the length of this fibre corre- sponds to the length of the work-piece that is to be bent. In bent condition the po- sition of the neutral line defines the dimensions. The greater the distance to the centre fibre in direction of the centre of the curvature, the shorter will be the neu- tral line and the shorter will be the unbent length. The length of an arc is calcu- lated as follows: ϕ π ⋅ ⋅ r 180 In practical life, compensation factors or gauge factors were introduced for differ- ent materials so as to calculate the length in unbent condition. First a work-piece to be shaped is designed in unbent condition. Thus the final dimensions are de- fined. Tables and diagrams indicating the gauge factor for a certain material, de- pending on sheet thickness and bending radius, were created in order to obtain the dimensions for cutting to size of sheets. We only have to add this value to the longitudinal dimensions of each curvature so as to receive the length in an unbent condition. Those tables and diagrams were generated during tests with different materials. Since the bending programme only uses contours and curvatures, the dimensions always refer to them. Thus, the coefficient of the position of the neutral line is used to calculate the length of the bending zones; the coefficient can be deduced from the compensa- tion factors. The gauge factors could be converted at once and be stored in a new table for the position of the neutral line. Open & Closed Sections/Trapezoidal Sections Strip Width Calculation © Copyright by data M Software GmbH 47 Nevertheless, the table of the gauge values was chosen as a basis for the calcu- lation of the programme, in order to get easy control of the values. It is highly probable that gauge factors for new materials will also be defined by tests so that they can directly be included in the table. In addition, recalculating the gauge fac- tor for each curvature does not involve major efforts. With the present bending programme the position of the neutral line was entered as a coefficient in relation to the thickness. For defining a curvature this coefficient is automatically pre-set to 0.5 in order to provide for a minimum of changes in ex- isting programmes. Only during positioning of a piece, i.e. in calculating and appending the individual elements of the work-piece the coefficient is calculated according to the material and depending on the bending radius and sheet thickness and the pre-set value will be overwritten. That enables you to proceed with the positioning of a new ma- terial at any moment. The coefficients will be redefined. 4.3. General Observations Calculating the coil stock width is mainly based on the following assumption: due to deformation and constriction of material, see Fig. 11, in the bending area con- nected with it, there will be a lengthening of the latitude co-ordinate of the work- piece with given retention of volume. In order to produce an arc element with a defined opening angle, and a median length of arc b, as necessary for the production of a profile required, you have to envisage a length element of the unformed material that corresponds to the me- dian length of the arc of the finished profile, minus lengthening. The value for the coil stock width of any profile required, results from the length of unfolding of a finished profile minus the total of elongation’s that occurred in the bending areas. Fig. 11 Constriction in bending areas Open & Closed Sections/Trapezoidal Sections Strip Width Calculation 48 © Copyright by data M Software GmbH All methods divide the profile into straights and arc elements for calculation. The calculation of the initial width according to methods 1 to 3 is done in two steps. First the theoretical lengthening is defined for each arc element of the profile, fol- lowing the respective calculation rules of the chosen method. The total of those lengthened is subtracted from the length of the profile after unfolding. And the re- sult will be the coil stock width required, as the total of those lengthened of all ref- erence zones, is the dimension by which the latitude co-ordinate of the material will be increased due to the shaping process. Fig. 12 Lengthening ∆b in a bending area A model depiction of the lengthened ∆b in a bending zone is shown in Fig. 12. It is supposed that the dimensions of straight sections will not change during shaping. These reflections will lead to an inconsistent alteration of material thickness within the transition zone between straight and arc elements. Nevertheless this approach should be maintained provided the following points are taken into consideration. It is known from studies that the material thickness s of bending areas reaches its minimum at the vertex of the curve and will only reach the original material thick- ness so far out at the adjacent side. We can assume that the surfaces between the real and the imaginary course of the external borderline have the same di- mension at each side of the transition in question. See also Fig 13. Fig. 13 Transition from straight to arc Thus, the transverse strain may be still defined on the basis of volume retention. The method according to S+B proceeds slightly different in detail. Open & Closed Sections/Trapezoidal Sections Strip Width Calculation © Copyright by data M Software GmbH 49 It approaches the arc elements with straight elements following certain rules. In combination with further gauge values depending on the bending angle one ob- tains the production width necessary for the arc element. Using the S+B method, the coil stock width for a profile, results from the total of the defined production widths for arc and straight elements. 4.4. Calculation in Accordance with German Standard DIN 6935 The German standard DIN 6935 on cold forming to shape includes a gauge factor K, which takes the longitudinal alterations, based on the bending process into ac- count. This factor indicates the difference between unbent fibre and centre fibre of an arc element and thus makes the calculations of the unbent fibre possible. 1 lg 2 1 65 . 0 ≤ ⋅ + = k s r k This standard is valid for bent pieces of flat steels dedicated to the use in mechanic engineering. Fig. 14 Position of the neutral line according to German standard DIN 6935 r : internal radius of the curvature s : material thickness β : opening angle a, b : leg length v : gauge factor L : stretched length L a b v = + + Thus, k/2 results for the coefficient of the position of the neutral line, since this coefficient refers to the thickness s. s k s 2 = ⋅ Koeff. The DIN standard uses the factor k to calculate the gauge value. In the pro- gramme however, you can immediately use the formula for calculation, since even the choice of a certain dimensioning method does not allow the generating of a homogenous table of gauge factors between German standard DIN and VDI guidelines. Open & Closed Sections/Trapezoidal Sections Strip Width Calculation 50 © Copyright by data M Software GmbH The conditions of this method which are to be taken into account regarding mate- rial and bending radii admitted are shown in DIN standard 6935. The table 15 shows a material key list that is to be used for calculations according to DIN 6935. steels with guaranteed minimum tensile strength steels up to 390N/mm2 over 390 up to 490 N/mm2 over 490 up to 640 N/mm2 gen. structural steels QST 34-2 QST 42-2 QST 52-e according to DIN 17100 QST 37-2 QST 42-3 QST 37-3 QST 46-2 Table 15 Table 16 lists minimum the bending radii (internal radius) admitted for the choice of certain material thickness values and materials. The indicated values are valid for bending angles α <=120°. For α >120° the following value in the table is to be inserted. Steels with during bending smallest bending radius r admitted for thickness s A guar- anteed cross- wise or over over over over over over over over over over over over over over L mini- mum parallel to 1 1 1.5 2.5 3 4 5 6 7 8 10 12 14 16 18 Tensile strength direc- tion up to up to up to up to up to up to up to up to up to up to up to up to up to up to N/mm2 of roll- ing 1.5 2.5 3 4 5 6 7 8 10 12 14 16 18 20 up to 390 cross wise 1 1.6 2.5 3 5 6 8 10 12 16 20 25 28 36 40 parallel 1 1.6 2.5 3 6 8 10 12 16 20 25 28 32 40 45 Over 390 up to 490 cross wise 1.2 2 3 4 5 8 10 12 16 20 25 28 32 40 45 parallel 1.2 2 3 4 6 10 12 16 20 25 32 36 40 45 50 over 490 up to 640 cross wise 1.6 2.5 4 5 6 8 10 12 16 20 25 32 36 45 50 parallel 1.6 2.5 4 5 8 10 12 16 20 25 32 36 40 50 63 Table 16 The lengthening of a bending zone is calculated with a non-dimensional correction factor K with a value between zero and one. This factor indicates the deviation towards the median line of an arc element and thus allows defining of the non- lengthened fibre. Open & Closed Sections/Trapezoidal Sections Strip Width Calculation © Copyright by data M Software GmbH 51 Fig. 17 Graphical depiction of the correction factor K The delta value for the bending zone is calculated with the following equation: ∆b a s K = ⋅ ⋅ ⋅ − π 0 1 360 ( ) opening angle α in (degrees) Depending on the specific inner radius R ( := inner radius/material thickness ), the calculation is subdivided into several process parts which deliver different values for the correction factor K. 1. R > 5 K = 1.0 2. 5 0 0 05 , , ≥ > R K = 0.65 + 0.5 * log(R) 3. 0 05 0 , ≥ ≥ R K = 0.0 4. 0.0 > R impossible after def of R This division allows covering all possibilities of an arc element regarding bending radius and opening angle relevant in practical life. Thus, the total of all calculated Db values has to be subtracted from the unfolding of the finished profile in order to define the coil stock width. 4.5. Algorithm according to Proksa In order to allow for an overall application, the calculation according to Proksa is subdivided into three calculation parts which are chosen and dependent on the specific inner radius R (:= inner radius/material thickness). The lengthening ∆b, which occurs in the zone of deformation due to the bending process, is calculated respectively. 1. R >5 ∆B = 0.0 2. 5 0 0 1 , , ≥ ≥ R ( ) [ ] 2 0 360 1 ) 1 ( 2 s s s r b i − ⋅ + − ⋅ ⋅ ⋅ = ∆ π α 3. 0 1 0 0 , , ≥ ≥ R ∆b s = + ⋅ ⋅ α π 360 0 0 12 , 4. 0.0 >R impossible after def of R The division method shown in the second line is based on calculation rules de- veloped by Proksa. Open & Closed Sections/Trapezoidal Sections Strip Width Calculation 52 © Copyright by data M Software GmbH In this formula the specific material thickness S (= current material thickness/initial material thickness) is used. Proksa uses a differential equation to calculate the specific sheet thickness S and for the modification to material thickness he uses S =s /so as a function of the specific internal radius R. ( ) ( )1 1 + ⋅ + − ⋅ = − − A A e R s e S dR dS with ⋅ − ⋅ + ⋅ ⋅ − ⋅ = χ χ χ 5 .0 1 5 . 0 1 ln 25 . 0 1 ln 2 2 S K A it is valid χ = ⋅ ⋅ + 2 2 S R S :curvature K k k v = ⋅2 0 :material factor kv :coefficient of hardening ko :yield point in shear The solution of this non-linear differential equation of first order is only possible with the numerical method of approximation. Here we chose the method of Runge-Kutta. For plane metal (condition before shaping) the value for the specific inner radius R = ri/so approaches the infinite set. As there is no constriction, the specific sheet thickness = 1.0. For practical calculation R has to be chosen high enough to be able to define a problem of initial value. In this application the values have been set in the following way. independent variable: R = 10.0 dependent variable: S = 1.0 The choice we made for the specific inner radius R is in any case sufficient be- cause even calculations with a much higher initial value for R confirm our choice. In order to proceed to a numerical solution we use an initial step of -1.0, which will be commanded variably during the calculation programme so as to reduce the error to a minimum. The solution range of the differential equation is also limited by the abscissa value R = 0.01 to the amount of values relevant for the calculation of the material width requested according to Proksa. Fig. 14 shows a depiction of these solutions for several material factors K. The solution curves are ending in the straight S = 1.0 with increasing R. As comparison the curves for ideal plastic-rigid (kv = 0.0) and ideal elastic material (ko = 0.0) are marked. Open & Closed Sections/Trapezoidal Sections Strip Width Calculation © Copyright by data M Software GmbH 53 Fig. 18 Alteration of material thickness s/so as function of specific inner radius ri/so The material factor K is a parameter of this differential equation and specifies the given characteristics of the material used for production. The definition of factor K requires the definition of the values kv and ko. For this purpose the yielding curve of the material is replaced by a straight. However, you have to make sure that the slope of this straight corresponds approximately to the slope of the yielding curve in the middle of the zone of adaptation. Also, you have to make sure that the sur- faces below the yielding curve and of the substitute straights are nearly of the same size in the middle of the zone, see Fig 19. It is useful to carry out this ap- proximation of the yielding curve with several straights, see Fig 20. Fig. 19 Approximation to the real yielding curve by a straight Using the example of the material UQST36, the determination of the factor K is to be shown. First of all the appropriate areas are defined. The curve sections of the different areas are approximated each by a straight in accordance with the above mentioned criteria. From a depiction as shown in Fig. 16, you can get the values required for the calculation of K. Open & Closed Sections/Trapezoidal Sections Strip Width Calculation 54 © Copyright by data M Software GmbH Fig. 20 Yielding curve for material UQST36 with substitute straights approximated for different areas The following interrelations are valid k k k r v 0 0 3 0 66 = = ⋅ , tanβ β : slope angle of substitute straights Now you may define the individual part of material K1 to K3 for the three areas in our example. You will obtain: K1 = 2.128 K2 = 1.021 K3 = 0.647 The arithmetic average of these three values is the material factor that is to be used for the material UQST36. KUQST36 = 1.27 With the information now available concerning material factor and differential equation, the latter can be solved. The result will be a table with the solution points (S; R) from which you can get the dependence of R and the value for the modifi- cation of material thickness S. With acceptable exactitude a linear interpolation can be used for intermediate points. The specific sheet thickness S has two appli- cations in the above method of calculating the ∆b value. As for the method in accordance with DIN standard 6935, all possibilities for an arc element regarding bending radius and opening angle, relevant in practical life, are covered by a sub-division into three steps. For the definition of the coil stock width the total of all calculated ∆b values is subtracted from the unfolding of the finished profile here. Open & Closed Sections/Trapezoidal Sections Strip Width Calculation © Copyright by data M Software GmbH 55 4.6. Algorithm in accordance with Bogojawlenskij The method according to Bogojawlenskij is based on the method of mathematical statistics. The measured values necessary for this purpose have been obtained especially from angle and U profiles. As explained in the previous section, the calculation of the coil stock width is based on the determination of the ∆b values for the individual bending areas. For carbon and low-alloy steels this value is obtained as a result of the following formulae which are chosen depending on the specific internal radius R. 1. R >5 ∆b = 0.0 2. 5 0 0 1 , , ≥ > R ∆ ∆ b n S B = ⋅ ⋅ 0 1172 0 1157 , , (mm) 3. 0 1 0 0 , , ≥ ≥ R (Falzung) ∆b s = ⋅ ⋅ ⋅ α π / , 360 0 12 0 4. 0.0 >R impossible after def of R nB : number of bending areas of a profile ∆s = so * 0.0032 * α0.53 * 1.26 * R-0.55 α : opening angle in degrees R : specific internal radius ri/so The equations mentioned under 2, and the formula for the determination if the ∆s value, have been developed by Bogojawlenskij only for applications with so = 1- 8mm, R = 5-35mm. α = 0-90° and material widths between 100mm and 350mm. The deduction is based on angles and U profiles as already mentioned. For this reason application is not recommended for all profiles. According to literature this method obtained very good calculation results for angle and U profiles. In accordance with the methods explained, the coil stock width results from the difference between unfolding of finished profile and total of all ∆b values. 4.7. Calculation in accordance with VDI guideline 3389 The VDI guideline 3389 page 3 deals with forming under bending conditions by wedge shaped tool with 90°. The indications of the document are especially des- tined to meet with high demands of 90° wedge-shaped bending and to forward tested standard values to practise. Those standard values were derived from re- sults of long-term statistical interpretation. The deviations of bent pieces caused by unequal quality within one kind of material can be neglected in practical life. Since each curvature is treated separately by the bending programme, it is suffi- cient to take V bending into account disregarding e.g. U shaping, since the pro- gramme interprets both curvatures as two V curvatures. Due to material strain during shaping, the non-lengthened fibre is placed in a posi- tion, which is not coaxial to the bending radius. Since the position cannot be de- fined in geometrical terms and thus is of no use in determining the stretched length, the gauge factors for bending angles of 90° have been determined by trial and error by bending tests. Open & Closed Sections/Trapezoidal Sections Strip Width Calculation 56 © Copyright by data M Software GmbH They are shown in diagrams in the VDI guideline 3389 page 3. On the basis of these gauge values the position of a theoretical neutral line required by the bend- ing programme is to be calculated. Fig. 21 Stretched length according to VDI s : thickness of the work-piece ri : internal radius of the curvature l1, l2 : internal side length L : stretched length x : gauge values L l l x = + + 1 2 Fig. 22 Stretched length according to the position of the neutral line a, b: lengths of the unmodified areas Koeff.: position of the neutral line ( ) ( )1 1 + ⋅ + − ⋅ = − − A A e R s e S dR dS Open & Closed Sections/Trapezoidal Sections Strip Width Calculation © Copyright by data M Software GmbH 57 The arc of the circle is calculated by ϕ π ⋅r 180 The radius of the neutral fibre results from the internal radius. By equating the two equations you will get an equation for the coefficient depending on the gauge fac- tor. As the gauge factors for an angle of 90° are included in the VDI guidelines, ϕ equals 90°. ( ) ( )1 1 + ⋅ + − ⋅ = − − A A e R s e S dR dS Fig. 23 Dimensioning according to VDI l1 and l2 can geometrically be divided into a, b and 2 * ri. Thus for the first equation is: L a b r x i = + + + 2 By equating results: ( ) 2 Koeff. 2 π ⋅ ⋅ + + + = + + + s r b a x r b a i i Resolution for the coefficient: This equation allows calculating a single valued coefficient using the values of bending radius, thickness of work-piece and material, as the gauge factor x is a function of these three values and no other parameter appears. If the material is in addition, compressed in the bending area, you will have to consider the stretching stress for each zone of shaping. 2 Koeff. 2 2 ⋅ ⋅ + = + π π s r x r i i π π ⋅ + − ⋅ = s x ri 2 ) 4 ( Koeff.