A nonlinear finite element method for electrostrictive ceramic multilayer actuators: A comparison of capacitor-type and slit structures

In this paper, we develop a nonlinear finite element method to study the reliability of ceramic multilayer actuators. The material is taken to be electrostrictive. Noticing the geometric characteristics of the multilayer actuators, we introduce the modified plane strain conditions which reduce the three dimensional problem to a two dimensional one. Then we develop a nonlinear finite element program to solve the electro-mechanical coupled problem. After the stress field distribution is solved, we apply the fracture mechanics to compute the stress intensity factors. As an example, a slit structure is compared with a capacitor-type structure. Numerical results show that slit structure is more reliable than the capacitor-type structure.