不同幅值激励的复合材料板时间反转损伤识别方法  

Damage Detection for Composites with Different Amplitude of Excitation by using Via Time Reversal Method

作　　者：周俊宇[1] 杨洋[1] 肖黎[1] 屈文忠[1] 

机构地区：[1]武汉大学工程力学系,武汉430072

出　　处：《机械科学与技术》2017年第2期298-302,共5页Mechanical Science and Technology for Aerospace Engineering

基　　金：国家自然科学基金项目(51378402)资助

摘　　要：复合材料结构受到冲击时会产生基体开裂、层脱等损伤,通常情况下损伤界面保持闭合接触。小幅值激励下应力波产生的应变极小,损伤界面仍处于闭合的线性状态,时间反转重构信号不能表明损伤的存在与否。针对该问题,采用不同幅值激励的时间反转方法进行损伤检测与识别,利用时间反转重构信号与激励信号的相关系数构造了损伤指数,开展了基于压电作动/传感阵列的复合材料板损伤识别与定位的实验研究。实验结果表明:小幅值激励下作动-传感的完整路径和损伤路径上的时间反转重构信号与原始激励信号相似程度均很高,不能表征结构中的损伤;而增大激励幅值至某一阈值后,损伤路径上的损伤指数明显增大,而完整路径上的损伤指数变化不明显;利用该方法准确地识别与定位了板中损伤。Matrix cracking and delamination may occur when composite structures exposed to impact. Generally, these crack interfaces remain closely contact. Such incipient damage may fail to be detected if the strain generated by the excitation is too small to open the contact interface. To overcome this deficiency, a new kind of damage detection for composites with different amplitude of excitation by using time reversal method is proposed. Applying different amplitude excitation voltage on the piezoelectric（PZT） transducers which are used to generate and receive Lamb wave signal, an experiment is set to detect impact damage in a composite plate based on the time reversal theory. Experimental results demonstrate that although the time reversal reconstructed signal is similar to which in an intact plate when a low amplitude excitation is applied, it does not indicate the presence of damage in the structure. When the excitation amplitude exceeds a certain threshold, the reconstructed signal would be different from the original excitation signal. Damage indexes of each path are defined with the correlation coefficient between the original excitation signal and the reconstructed signal. An imaging algorithm is developed to locate the impact damage on the plate. It turns out that the damage can be accurately detected and located.

关 键 词：复合材料板 损伤识别 时间反转 激励幅值 

分 类 号：V214.8[航空宇航科学与技术—航空宇航推进理论与工程]