基于PWAS的层合板导波传播特性和损伤响应FEM分析及试验验证

导波无损检测（Non-Destructive Testing, NDT）技术由于适用范围广、检测速度快等优势，已成为结构安全性检测的重要技术手段之一。不过，导波在各向异性介质中的传播表现为频散特性与波传播方向的关联性、多模态特性与各向异性的相互作用以及不同模态与损伤的相互作用。导波在复合材料无损检测应用中的复杂性对检测技术和检测方法提出了更高的要求，所以对碳纤维复合材料层合板中的导波传播特性和损伤响应进行分析具有十分重要的意义。文中采用理论分析、仿真和试验相结合的方法，对不同碳纤维增强聚合物基（Carbon Fiber Reinforced Polymer, CFRP）层合板中的导波传播特性和各模态波与损伤的相互作用进行了分析。首先根据群速度、波长等参数建立有限元模型，并在边界设置阻尼递增吸收区域来弱化边界反射波的干扰；然后分析基于压电晶片有源传感器（Piezoelectric Wafer active Sensors, PWAS）的不同层合板中导波传播差异，之后在结构中引入损伤来分析不同模态波与不同损伤的相互作用；最后通过试验分析和验证有限元仿真的准确性。

FEM Analysis and Experimental Verification of Guided Waves Propagation Characteristics and Damage Response of Laminates Based on PWAS

Guided wave non-destructive testing (NDT) technology has become one of the important technical means for structural safety inspection due to its advantages such as wide application range and fast detection speed. However, the propagation of guided waves in anisotropic media shows the correlation between dispersion characteristics and wave propagation direction, the interaction between multimodal characteristics and anisotropy, and the interaction between different modes and damage. The complexity of the application of guided waves in non-destructive testing of composite materials puts forward higher requirements on the inspection techniques and methods, so it is of great importance to analyze the propagation characteristics and damage response of guided waves in carbon fiber composite laminates. In this paper a combination of theoretical analysis, simulation and experimental methods is used to analyze the propagation characteristics of guided wave and the interaction of each mode with damage in different carbon fiber reinforced polymer laminates. Firstly, a finite element model is established based on parameters such as group velocity and wavelength, and a damped incremental absorption region is set at the boundary to weaken the interference of reflected waves at the boundary. Then, the difference of guided wave propagation in different laminates based on piezoelectric wafer active sensors (PWAS) is analyzed, and after that damage is introduced into the structure to analyze the interaction between different modal waves and different damages. Finally, the accuracy of the finite element simulation is analyzed and verified experimentally.