A New Strong Form Technique for Thermo-Electro-Mechanical Behaviors of Piezoelectric Solids

Piezoelectric materials are widely fabricated and investigated for potential applications in microelectromechanical systems as direct converters between mechanical and electrical signals, where some show pyroelectric features involving thermo-electro-mechanical interactions. This study aimed to introduce a novel numerical technique to predict the thermo-electro-mechanical behaviors of piezoelectric structures, based on a strong-form numerical framework called the element differential method. In this method, the shape functions of the isoparametric element and their first two derivatives were derived analytically by interpolating the temperature, displacement, and electric potentials. Then, a point collocation method based on node positions in the elements was proposed to generate the final system of equations without any domain integrations. Thus, the coupled behaviors of thermal piezoelectric structures, including the pyroelectric features, can be simulated by the strong-form formulation of the governing equations. Several numerical examples, including the piezoelectric composites structures, are presented, and the coupled thermo-electro-mechanical responses have been analyzed to validate the proposed method.