Mixed Piezothermoelastic Finite Element Model for THUNDER Actuators

摘要

This paper presents a mixed piezothermoelastic finite element model for a special THUNDER (thin-layer unimorph ferroelectric driver) actuator's structures. In the mixed piezothermoelastic model, an element includes four displacement nodes, eight temperature nodes, and two potential nodes. Dynamic analyses are implemented to investigate the thermal deformation during the cooling process, deflection caused by the repolarization in the repoling process, and the piezothermoelastic coupling effect in the actuating process. The relationships between these three types of dynamic behaviors are developed by using their initial displacements. Numerical examples are given to demonstrate the proposed model and method. The accuracy of the computational results obtained by using the mixed piezothermoelastic model is sufficient. The THUNDER actuator has good properties on both actuating deflection and resisting load. In engineering applications, thermal strains have a significant effect on dome height, although thermoelectric coupling is relative small but still noticeable. Numerical results show that piezothermoelastic dynamic analysis is necessary for a THUNDER actuator to be used more effectively and accurately.