Spectral Analysis of Suface Waves Combined to Laser Ultrasonics for the Non‐Destructive Testing of High Performance Materials and Composites

Recently, a signal processing technique for ultrasonic waves has emerged, which is used in seismology or for the analysis of the mechanical properties of concrete multilayers or pavements. This technique is called spectral analysis of surface waves (SASW) and examines the variations in the velocity of the Rayleigh waves as function of wavelength and frequency. We present SASW experimental results obtained on multilayered materials using high frequency laser‐ultrasonics. We used the 2D‐FFT method to obtain representations of surface wave velocities at high frequencies.