Ducousso, Mathieu; SAFRAN; France
Adl-Zarrabi, B.; Chalmers University of Technology; Sweden
Lidén, H.P.; Chalmers University of Technology; Sweden
Session: Composite Material - UT 1
Time: 10:50 - 11:10
This work aims to demonstrate the capability to evaluate the bulk thermal ageing of aeronautical composites materials using Lamb waves. Composite materials are bidimensional woven composite structures with polymer. More than twenty different thermal ageing were obtained by modulating the temperature and the duration of the cure. Impact on material properties was evaluated using normalized destructive characterization.
Lamb waves are generated and detected using a single 3 MHz phase array transducer in contact with the composite structure. In that way, a B-Scan image of the acoustic propagation in the composites material is obtained. The dispersion curve are then calculated using a bidimensional Fourier Transform (Bi-FFT) or using a singular values decomposition (SVD) to project the experimental data into the wavenumber-frequency domain. Both methods allow an accurate estimation of the Lamb wave dispersion curves .
Thermal ageing is then evaluated from a numerical comparison between an experimental and a numerical database of dispersion curves corresponding to different thermal ageing.
Results are promising – more than 85 % of successful evaluation were obtained – and open the doors toward quantitative evaluation of thermal ageing of composites materials on the runway.