基于挠曲电传感阵列的悬臂梁结构损伤监测研究

Structural health monitoring is an important link in the safe operation and maintenance of aircraft, and sensors, as the forefront of structural state information sensing, are crucial for structural health monitoring. Aiming at the existing piezoelectric materials, which are subject to many limitations in terms of material selection range and service temperature as well as environmental protection, the application of flexoelectric sensors and their arrays in the field of structural health monitoring is explored by taking the cantilever beam structure as an example. Firstly, based on the sensing principle of flexoelectric sensors in cantilever beam structure, the frequency response function of flexoelectric sensors for curvature measurement in cantilever beam structure is derived, and the effectiveness of flexoelectric sensing array for curvature modal measurement is experimentally verified. Then a flexible and stretchable flexoelectric sensing array is designed and prepared by using a flexible electronic process. Finally, cantilever beam monitoring experiments were carried out to evaluate the damage identification capability of the sensing array, and the results show that the normalized modal flexoelectric signal difference can be used to identify the number and location of cracks. This work provides a new way for structural health monitoring, expands the application range of flexoelectric effect, and has important guiding significance for flexoelectric toward structural health monitoring of aircraft.