Finite element model verification for the use of piezoelectric sensor in structural modal analysis

摘要

This paper presents the theoretical modal analysis for the use of PVDF sensor in structural modal testing via finite element analysis (FEA), A series of rectangular PVDF films are adhered on the surface of cantilever beam as sensors, while the point impact force is applied as the actuator for experimental modal analysis (EMA). Natural frequencies and mode shapes determined from both FEA and EMA are validated. In FEA, the beam structure is modeled by 3D solid elements, and the PVDF films are modeled by 3D coupled field piezoelectric elements. Both modal analysis and harmonic response analysis are performed to obtain the structural modal parameters and frequency response functions, respectively. Results show that both FEA and EMA results agree well. In particular, the PVDF sensor mode shapes, proportional to the slope difference between the two edges of PVDF film, are numerically and experimentally validated by FEA and EMA, respectively. Therefore, the simulation of PVDF films for vibration analysis in FEA can be verified and easily extended to other complex structures that may contain piezoelectric materials.