Finite Element Analysis of ElectrostaticCoupled Systems: Using GeometricallyNonlinear Mixed Assumed Stress FiniteElements

Multi-physics coupled fields are often present in MEMS. This makes the modeling and analysis of such devices difficult and sometimes costly. The coupling between electrostatic and mechanical fields in MEMS is one of the most common and fundamental phenomena in MEMS; it is this configuration that is studied in this thesis. The following issues are addressed: 1. The finite element method (FEM) is therefore used to model electrostaticmechanical coupled MEMS. 2. In order to capture the configuration of the system accurately, with relatively little computational effort, a geometric non-linear mixed assumed stress element is developed and used in the FE analyses. 3. Selected algorithms for solving highly non-linear coupled systems are evaluated. 4.Finally, a practical engineering MEMS problem is studied.