Incorporating geometrical nonlinearities in reduced order models for MEMS gyroscopes

We present a method to incorporate geometric nonlinearities in a linear reduced order model of a MEMS gyroscope. We use a prestressed modal analysis in ANSYS to generate stiffness matrices for the reduced order model (ROM). Using a look-up table for the stiffness matrices, we perform transient simulations in Matlab/Simulink. We compare the results of our model to measurements of a benchmark MEMS structure. By our approach, we are able to model geometrical nonlinearities with good accuracy and low computational effort, thus predicting typical frequency shifts in MEMS gyroscopes.