Failure Analysis and Experimental validation of MEMS Gyro under random Vibration condition

MEMS gyros installed in modern complex systems, like aircraft systems and industrial control system, are mainly subjected to mechanical vibrations in applications. Therefore, the failure of the MEMS gyro under random vibration was studied by the finite element method (FEM) and step test in this paper. Firstly, the mechanism of the output accuracy reduction of MEMS gyro under random vibration was analyzed. Then the displacement variation of MEMS gyro's sensitive structure in three different directions and the stress distribution under random vibration was analyzed by FEM, and the results showed that the key failure location of the MEMS gyro is the intersection of the slanted beam and the trapezoidal beam. MEMS gyros have been tested to failure by subjecting to a wide-band (15Hz-2KHz) random vibration step test with root mean square accelerations of 3g, 6g, 25g, 30g, 35g, 45g, 50g, 55g, 60g and 62.5g. The test results showed that the MEMS gyro can withstand a limit root mean square acceleration of 62.5g, and the failure position is consistent with simulation results by FEM, the reason of the failure was analyzed.