A FINITE ELEMENT SIMULATION METHOD OF PIEZOELECTRIC WAFER ACTIVE SENSORS WITH MECHANICAL ELEMENTS

Piezoelectric wafer active sensors (PWAS) are widely used to generate and receive ultrasonic guided waves (UGW), and have shown great potentials in structural health monitoring (SHM) applications. Modeling as well as simulation for interaction between PWAS and host structure plays an important role in the SHM applications. Due to the complex coupled field and UGW propagation, numerical simulation via finite element (FE) method is introduced. When modeling the coupled fields between PWAS and the host structure, electro-mechanical interaction usually be considered, leading to the modeling complexity and time-consuming. This paper presents an FE method which just considering the mechanical elements to simulate the excitation and receiving process of PWAS. In the model, the effect of PWAS can be simulated by applying a series of in-plane forces. Based on the reciprocity theorem, the receiving voltage amplitude can also be calculated by in-plane displacement data of the structure surface. Theoretical analysis has been conducted to validate the feasibility of proposed method. And an FE model with 3D deformable solid elements is also implemented. Furthermore, an experiment of crack detection on an aerospace grade aluminum sheet metal alloys, which is the same as FE model, was designed using an array of PWAS to validate our method.