Numerical model and experimental validation of stress waves propagation in large composite panels

This study investigates stress waves application for non-destructive inspection and structural health monitoring in large laminated composite panels. This study investigates Lamb wave dispersion under two boundary conditions: fixed support and simply support. Lamb wave propagation is examined under two conditions: one with a 100 kHz excitation frequency to simulate internal defects, and the other with a 30N impulse load to simulate external events. Both scenarios include cases with and without cutouts. Experimental and numerical analyses are conducted to examine stress wave propagation characteristics in these panels. The experimental phase focuses on discerning propagation time differences attributable to cutouts, while the three-dimensional (3-D) numerical model analyses propagation time, path, and frequencies. Results reveal a significant time discrepancy between panels with and without cutouts, indicating that cutouts introduce delays in wave propagation due to disruptions in the propagation path. Comparative analysis affirms the reliability and accuracy of the numerical approach, aligning with outcomes from the experimental approach. This research contributes insights into stress wave behaviour, demonstrating its potential for effective non-destructive inspection and structural health monitoring in laminated composites across diverse structural applications.