Stress Analysis on the Folded Beams of a MEM Accelerometer

The elastic behavior of a system can be determined by the stress analysis. This knowledge is useful in order to not exceed its limit of elasticity that means, to avoid permanent deformations, which can totally modify the performance of the system. In this paper, theoretical and simulated results of the normal stress generated in the folded beams of an accelerometer, under constant acceleration, are presented. The system under analysis has a suspended mass by means of four flat beams. The analysis was realized considering a cantilever, because this element is used as beam of support. A uniformly distributed load is present on the suspension beams. In simulations, 1g (9.81 m/s2) was applied to several accelerometers with different dimensions and geometries, with the purpose of observing that the normal stress should not exceed the elastic limit of silicon.