On the hygro-thermo-electro-mechanical coupling effect on static and dynamic responses of piezoelectric beams

In the present paper, for the first time, piezoelectric beams under multi-physical hygro-thermo-electro-mechanical (HTEM) coupling is analyzed using the node-based smoothed radial point interpolation method (NS-RPIM). The GS-Galerkin weak formulation is utilized to obtain discretized governing equations. The elastic coefficients are assumed to be linearly dependent on temperature and moisture. The static and dynamic responses of the piezoelectric beams are investigated using the developed the NS-RPIM based beam model at different hygrothermal conditions. Effects of the damping ratios and the hygrothermal parameters on the generalized displacements and natural frequencies of the clamped energy harvester with different combinations of inside holes are comprehensively discussed. Additionally, the high accuracy and excellent convergence rate of the proposed method are also validated by using a piezoelectric cantilever beam with HTEM coupling. The presented NS-RPIM based two-dimensional beam model can be used for future studies of the coupled multi-physical problems as well as investigations of complex piezoelectric sensors and actuators in a hygrothermal environment.