基于时间反转法的曲板高速冲击定位研究

The research on identifying the high velocity impact in curved plate is an essential studies in structural health monitoring, for the outside structures of aerospace vehicles are mainly in curved shape. Time-reversal (T-R) method has been used to trace the location of source widely because of its self-focusing characteristics. In the proposal, a location detection method based on time-reversal (T-R) principle is developed to detect the high velocity impact in curved plate structures. The investigation is concentrated on finding the focusing characteristic of the T-R model for curved plate and solving the problems related to high velocity impact in location detection method. The relationship between the characteristic parameter of the reconstructed signals and the focusing characteristic of T-R model is discussed, and the multi-characteristic parameters are selected for location detecting, finally the high velocity impact experiments on curved metallic plate by air gun is completed to validate the T-R model and the detecting method. Based on the final element simulation and the impact experiments, the factors which affect the results of impact detection are obtained, and the complementation of the information in time domain and space domain is revealed. The results is important for monitoring high velocity impact in complex structures, the understanding of the time-space focusing mechanism of T-R method, and the application of T-R method in structural health monitoring.

航空航天器的外层结构大多是曲面形状，曲板高速冲击定位研究是结构健康监测领域中的重要课题。时间反转法由于其良好的自聚焦特性在位置识别中有良好的应用前景，本项目将基于时间反转法的冲击载荷识别方法进一步拓展应用到曲板结构的高速冲击定位，主要探索曲板冲击时反模型的聚焦规律，基于聚焦特性建立位置识别方法并解决该方法中由高速冲击引入的问题。分析重构冲击信号的特征参数与时反模型聚焦特性的关系，提出利用重构冲击信号的多重特征值进行位置识别的途径，最后通过金属曲板气炮高速冲击实验验证模型的可行性和定位方法的适用性。在有限元仿真分析和冲击实验研究的基础上，讨论影响时反法定位的因素，揭示模型中信息在时间上和空间上的互补性。研究结果对复杂结构高速冲击监测研究有重要价值，同时对理解时间法的时空聚焦机理及其在结构健康监测领域的应用有重要作用。