针对不连续带洞结构的声发射源定位方法研究

由于兰姆波在舷窗等带孔结构表面的传播路径不再是线性路径,传统方法难以解决撞击的声源定位问题。 本文针对该问题,提出了一种基于声发射的网格映射概率成像定位方法。 该方法通过建立网格映射模型解决了信号传播的非线性路径难题,并通过对网格节点的信号最快传播路径计算得到相应的理论时间差值。 之后利用自适应能量阈值方法与 AIC 方法计算信号的实际到达时间差,通过比较理论值与实际值的偏差构建概率图像以实现定位解算。 通过有限元模拟分析了带洞结构对兰姆波传播路径的影响,给出信号传播路径的确定依据。 通过对 32 个撞击点的定位实验验证了定位方法的可行性,平均绝对误差为 1. 15 cm。

Research on acoustic emission source localization method for discontinuous structure with holes

It is difficult to solve the acoustic source localization problem of impact with the traditional methods since the propagation pathof Lamb waves on the surface of porthole structure is no longer a linear path. To address this problem, a grid mapping probabilisticimaging localization method based on acoustic emission is proposed in this study. This method solves the nonlinear path problem of signalpropagation by establishing a grid mapping model, and the corresponding theoretical time difference is obtained by calculating the fastestpropagation path of signal at the grid nodes. Then the actual arrival time difference of signal is calculated by using the adaptive energythreshold method and the AIC method, and the probabilistic image is constructed by comparing the deviation of theoretical value withactual value to obtain the localization solution. The influence of band-hole structure on the propagation path of Lamb waves is analyzed byfinite element simulation, and the basis of determining the signal propagation path is given. The feasibility of localization method is alsoverified by the localization experiments on 32 impact points, which provides an average absolute error of 1. 15 cm.