Time Domain Simulation And Analysis Of Composite Bonded Structures Based On Ultrasonic Transmission Characteristics

Based on the principle of ultrasonic testing, the non-contact ultrasonic time-domain simulation testing method was developed for the debonding and weak bonding defects of composite structures. Firstly, the time-domain simulation model of the ultrasonic transmission characteristics of single-layer CFRP (carbon fiber reinforced polymer) plate is established, and the frequency spectrum of the transmission coefficient is obtained. By comparing with the plane wave theory, the results show that the simulation results are in good agreement with the theoretical calculation. Then, the ultrasonic transmission coefficient of single / double interface weakening and cohesive weakening in composite bonding structure is simulated. The simulation results show that with the decrease of interface stiffness and the deepening of cohesion weakening, the local extreme points in the transmission coefficient spectrum tend to shift to the low frequency side, and the offset of the extreme points caused by the decrease of spring stiffness is different at different frequency points.