高 g 值微机电系统加速度传感器可靠性的 相场分析方法

：To address structural failures in high-g micro-electro-mechanical system （MEMS） accelerometers under extreme shock environments，a reliability analysis method using the phasefield fracture model was proposed.Based on phase-field fracture theory，a reliability analysis workflow encompassing failure mode identification， crack evolution simulation， structural improvement，and re-validation was established.The micro-scale processes of crack initiation and propagation were quantitatively and visually characterized through static and transient analyses combined with a phase-field fracture model.The numerical results were comparatively validated against three-dimensional high-g shock test results.On this basis，a fillet improvement design was proposed for the high stress concentration region at the torsion-beam root，and the fracture resistance of the improved scheme was evaluated via static and transient re-analysis together with phase-field fracture-based comparative validation.The results indicate that pronounced stress concentration at the torsion-beam root is the dominant region governing crack initiation and propagation，thereby revealing the relationship between stress concentration and crack evolution. The proposed beam-root fillet improvement design reduces stress concentration by approximately 18% and delays crack propagation by about 40%，thus improving the fracture resistance reliability of the sensor under high-g impact conditions.This study provides a feasible solution for the reliability analysis of high-g MEMS accelerometers.