The hygro-thermo-electro-mechanical coupling edge-based smoothed point interpolation method for the response of functionally graded piezoelectric structure under hygrothermal environment

Abstract

In this paper, we analyze the hygro-thermo-electro-mechanical (HTEM) coupling problem of functionally graded piezoelectric (FGPE) structure based on edge-based smoothed point interpolation method (ES-PIM). The basic equations for FGPE structure are derived in the multi-physical field. Triangular elements adopted in ES-PIM can be generated automatically and suitable for complicated structures. The responses for the HTEM coupling problem are calculated by ES-PIM and finite element method (FEM) under different hygrothermal conditions. Through the numerical examples, the factors related to the temperature and moisture fields are explored. The exponential factor and the hygrothermal effect on the responses of the FGPE structure are also studied. Besides, the advantages of proposed method for HTEM coupling problems are also validated by several numerical examples. These solutions also indicate that the increase of temperature and moisture concentration decreases the structural stiffness when empirical constants are set to negative numbers, leading to the decrease of frequency and variation of displacement. This article proposes an excellent numerical method and provides a reference for the design and application of piezoelectric structures.