中文摘要：

针对当前板类结构应力检测方法的不足，提出一种基于非线性声弹性效应检测应力的方法．该方法利用声弹性运动方程和Rayleigh—Lamb频率方程，绘制了4mmQ235钢板中SO、AO与SH0模态的频散曲线与波结构图，并对不同激励频率下上述模态的群速度相对变化率进行了理论计算与有限元模拟仿真．结果表明：sO模态的声弹性效应较A0模态与SH0模态更敏感，且声弹性效应最敏感的激励频率为频散较弱的90～150kHz；声弹性效应与所激励模态的波结构有关，沿应力方向面内位移越大声弹性效应越显著．

英文摘要：

Aim at the deficiency of plate structure online stress monitoring, a new method of online stress monitoring based on the theory of acoustoelasticity for guided wave was proposed. The disperse curves and mode shapes were calculated for 4 mm Q235 steel plate based on equations of acoustoelastic motion and Rayleigh-Lamb frequency, and relative variable ratios of group velocity were calculated in theoretical equations and finite element simulation for different frequencies. Results show that SO mode is more sensitive than A0 mode and SH0 mode for acoustoelastic effect, and the optimal excitation frequency range for acoustoelastic effect is 90 - 150 kHz that is weak dispersion; aeoustoelastic effect is related with mode shapes of excitation mode, and the larger the in-plane displacement, the more significant is the acoustoelastic effect.