基于PVDF传感器和工作曲率变形实现裂纹梁裂纹检测

Crack Detection for Beam Structures Based on Operating Curvature Deflection Shape Using PVDF Sensors

提出通过压电高分子薄膜PVDF(Polyvinylidene Fluoride)作为传感器直接测量结构的工作曲率变形(Curvature Oper-ating Shape)实现结构裂纹检测。以悬臂裂纹梁为例,首先探讨基于PVDF传感器测量工作曲率变形,并用于结构损伤检测的可行性,然后介绍工作曲率变形用于损伤检测的理论基础,并以PVDF压电薄膜作为传感器,提出只通过损伤后结构的频率响应函数,直接得到工作曲率变形和损伤指标。最后通过对一条裂纹和两条裂纹悬臂梁的损伤检测实验,证明该方法在梁结构损伤识别和健康监测中的有效性,并且识别过程不需要健康结构的振动信息。

With an example of a clamped-free cracked beam, a decision method for structural damage detection based on operating curvature deflection shape, which is measured by a piezoelectric polymer （polyvinylidene fluoride,PVDF）film as sensor mounted onto the structure surface is presented in this paper. First, the theory of damage detection based on operating curvature deflection is introduced. And then the operating deflection shapes and damage index are direct determined from the frequency response functions of the damaged structures by using PVDF film as sensor. Final, the experimental woks for one and two-cracked aluminum beam were performed to verify the proposed method. The successful detection of cracks in the beam demonstrates that the proposed method can be used efficiently in damage identification and health monitoring of beam-type structures. The main advantage of the proposed method is without need of the health structures vibration information.