Numerical analysis of the effect of poling-loading misalignment and mechanical boundary conditions on piezoelectric actuation

Purpose - The paper aims to highlight the computational implementation of a nonlinear piezoelectric constitutive model and its application in determining the impact of misalignment between initial poling direction and applied electrical field, and mechanical boundary conditions on actuator performance. Design/methodology/approach - The numerical analysis is based on an existing three-dimensional model, where the original rate-independent evolution equations are replaced by their rate-dependent counterparts to facilitate implementation, which is performed in a partial differential equation solver. The execution of the model is verified through several benchmark constitutive responses. Findings - The analysis shows that small angles of poling and loading axes misalignment such as may occur in fabrication (less than 5 degrees) have minor impact on piezoelectric performance regardless of the type of imposed mechanical boundary conditions. On the other hand, larger angles of misalignment can have a significant impact, the feasibility of which in actuator design remains to be seen. Furthermore, it is shown that the linear response range of these actuators can be expanded by increased levels of mechanical constraint at the cost of maximum actuation stroke regardless of the degree of misalignment. Originality/value - The misalignment, which occurs accidentally, but can also be introduced purposefully during the fabrication process when poled material is cut into specimen form, may exhibit desirable performance features for actuator design when combined with appropriate mechanical constraints.