板中Lamb波激励响应计算方法

采用基于半解析有限元的激励响应计算方法来求解薄板中Lamb波的激励响应结果,替代常规的实验方法,实现对薄板中Lamb波传播特性的仿真分析。与三维有限元仿真方法相比,采用激励响应计算方法仿真导波在波导介质中的传播过程可以节省计算量,提高效率。通过求解薄板中Lamb波的一般均质方程,基于频谱叠加原理,可以计算薄板中Lamb波激励响应结果。分别提取激励响应计算结果和实验测量数据,通过小波分析计算两种数据的Lamb波群速度。经验证,激励响应仿真计算结果与实验数据有很好的一致性,通过群速度频散曲线对比两种方法获取的数据,模态分析结论一致。激励响应计算方法还可以仿真计算任意截面波导介质中导波的传播过程,具有较好的通用性。

A Calculation Method of Lamb Waves Excitation Response in a Plate

In order to analyze Lamb wave propagation characteristics, a response calculation method based on a semi-analytical finite element is used to solve the Lamb wave excitation response in a plate instead of the conventional experimental method. Compared with the three-dimensional finite element simulation method, simulating the propagation process of guided wave in waveguide medium, via measuring the response of stimulation, can improve the computational efficiency. The Lamb wave excitation response is derived from the previous system functional model by solving the general homogeneous equation of the Lamb wave in the thin plate based on the principle of spectral superposition. For both response and experimental data, the wavelet transform is used to calculate Lamb waves'' group velocities. Experimental results are in good agreement with the data obtained by excitation response calculation method. In addition to that, the modal analysis shows consistency. Moreover, the excitation response calculation method is a versatile approach, which can also be used to simulate the propagation process of the guided wave in any section waveguide medium.