主动Lamb波监测技术中的传感元件优化布置研究

研究了应用主动Lamb波对复合材料结构试件进行损伤检测时的压电元件的布置优化问题.首先,通过实验选取了不同中心频率的激励信号对结构板进行激励,根据Lamb波响应信号的分析结果对各个压电元件之间的距离进行优化;其次,通过计算S0模式Lamb波的群速度获得边界反射的到达时间,将计算得到的边界反射信号的发生时刻与实际情况进行对比,结果吻合一致,据此可对压电元件进行抑制边界反射影响的优化布置.将压电元件的优化布置应用在具体的损伤检测实验中,实现了复合材料上的一维结构脱层损伤定位.

Optimization for Collocation of Sensors in Active Lamb Wave-based Monitoring

The propagation characteristics of Lamb waves in composites are researched.Actuation signals with different central frequencies are used to excite composite plate.According to the response of Lamb wave signals,it is applicable to optimize the location of sensors for each other to prevent the superimposition of different modes of Lamb waves and produce the single mode for the convenience of analyzing.Also,according to the arrival time of border reflection,which can be obtained by the calculated group velocity of S_0 mode of Lamb wave,the collocation optimization of sensors for resisting the disturbing of border reflection can be realized.It can be validated that the calculated arrival time of border reflection agreed well with the real.Based on the optimization for collocation of sensors,to suppress the superimposition of different modes and delay the arrival time of border reflection,the localization of delamination in composite is accomplished with the produced single mode signals.