Three-dimensional assumed strain solid element for piezoelectric actuator/sensor analysis

This paper deals with a fully coupled assumed strain solid element that can be used for simultaneous modeling of thin sensors and actuators. To solve fully coupled field problems, electric potential is regarded as a nodal degree of freedom in addition to three translations in an eighteen node assumed strain solid element. Therefore, the induced electric potential can be calculated for a prescribed deformation or an applied load. Since the original assumed strain solid element is free of locking, the element can be used to analyze behavior of very thin actuators without locking. Numerical examples, such as a typical bimorph actuator/sensor beam problem shows that the present element can handle fully coupled problems. Using the solid element, we have analyzed the actuation performance of THUNDER and compared the result with measured data. The. comparison shows that the numerical estimation agrees well with measured displacement for simply supported boundary condition. It is also found that a particular combination of materials for layers and curvature of THUNDER improve actuation displacement.