Lamb Wave Excitation Simulation and Monitoring Signal Pattern Recognition in Thin Plate

By means of the transient dynamic method of ABAQUS/Explicit, simulation of lamb wave generated by single-point excitation and double-point symmetric excitation in thin aluminum alloy plate is completed. The response characteristics of lamb wave under different excitation methods were studied. And the modified wave velocity method was used for pattern recognition of monitoring signal. The results show that the signal envelope and the modified wave velocity method can accurately identify the different modes of lamb wave, and the arrival time error of the wave packet is less than 2%; With single-point excitation, the amplitude of the S
₀
mode is very small, therefore, a lamb wave in A
₀
mode approximate to a single mode can be obtained; When using a double-point symmetric excitation, the amplitude of the A
₀
mode is small, and a lamb wave in S
₀
mode approximate to a single mode can be acquired; With double-point symmetric excitation, the noise is more pronounced than that of single-point excitation, while single-point excitation has almost no noise. The simulation results can effectively support the optimization of health monitoring excitation scheme for thin plate structure based on lamb wave.