3D Terahertz Imaging for the Control of
Aeronautics Composite Multilayered Structures
F. Ospald", W. Zouaghi", D. Moltera and R. Beiganga
aDepartment of Physics and Research Center OPTIMAS, TU Kaiserslautern, 67663 Kaiserslautern, Germany
J.-P. Guilletb, J-B. Perraultb, I. Manek-Honningerb and P. Mounaixb
bLOMA, Bordeaux 1 University, CNRS UMR 4798,351 cours de la Liberation, 33405 Talence, France
Abstract-We present results from a TDS imaging system for
non-destructive evaluation of aeronautics composite materials,
like glass fiber laminate and sandwich structures. Time-of-flight
information from reflection measurements allows for 3D
reconstruction of test sample volumes. Clear identification and
spatial positioning of defects like delamination and foreign
inclusion is possible.
I. INTRODUCTION AND BACKGROUND
ITHIN the scope of the DOTNAC projectl, the
potential of THz imaging and analysis for the non
destructive investigation of composite materials from the
aeronautics industry should be evaluated.
A special TDS system was designed for the project; it
utilizes ECOPS for fast data acquisition and is fully fiber
integrated to enable in-the-field use and remote sensor heads
with six meters position range from the operational base unit.
Two reference systems were available to explore the THz
detectability of various defects under optimal conditions and
validate the results of the fiber-integrated device. Furthermore,
data from established NDT tools such as X-ray, ultrasound,
and infrared techniques were available for comparison.
Over seventy samples have been fabricated and examined
during the project (see Fig. Ib where XY and XZ images are
provided). These include solid glass fiber laminates as well as
GFRP A- and C-sandwiches, and additionally CFPR panels.
Defects are foreign objects, debonds and delaminations,
impact damage and water contamination for the GFRP
samples and impact damage or coating misprocesses for the
TDS imaging facilitates detection