基于Lamb的金属薄板损伤主动监测技术研究

Technical Research on Active Detection and Monitoring of Damage in Metallic Plate Based on Lamb Wave

开发了一个主动嵌入式多激励健康监测系统,介绍了利用Lamb波进行损伤监测的原理和流程,测试了试验用铝板的群速度频散曲线。分别利用不同的压电陶瓷(PZT)片作为激励端和响应端,进行了不同传播路径的试验测试,对损伤前后的不同传播路径的测试波形进行分析处理和比较,找到了反映损伤前后波形变化的规律。利用散射波能量与基准能量的比值定义了损伤率的概念,以孔洞损伤为例计算了损伤对不同传播路径损伤率的数值影响,结果表明该特征值可用来实现对损伤位置的判断。

A built-in active multiple-actuator structure health monitoring system was developed, and the flow chart and the principle of damage detection using lamb wave was introduced. The frequency dispersion of the testing aluminum plate was measured, and the measurements on some diagnose paths were completed using different PZT as actuators and sensors. The response data of damaged and undamaged were analyzed and compared, the rule of the wave pattern change was found. The damage index was defined as the ratio of scatter energy to baseline energy, the influence of hole on damage index of different diagnose path were given, and the results showed that this feature could be used to identify the location of the damage.