Dipartimento di Ingegneria Strutturale, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy.
Sensors (Basel). 2012 Oct 17;12(10):13985-4003. doi: 10.3390/s121013985.
In this paper, the mechanical response of a commercial off-the-shelf, uni-axial polysilicon MEMS accelerometer subject to drops is numerically investigated. To speed up the calculations, a simplified physically-based (beams and plate), two degrees of freedom model of the movable parts of the sensor is adopted. The capability and the accuracy of the model are assessed against three-dimensional finite element simulations, and against outcomes of experiments on instrumented samples. It is shown that the reduced order model provides accurate outcomes as for the system dynamics. To also get rather accurate results in terms of stress fields within regions that are prone to fail upon high-g shocks, a correction factor is proposed by accounting for the local stress amplification induced by re-entrant corners.
本文数值研究了商业现货、单轴多晶硅微机电系统加速度计在跌落情况下的力学响应。为了加快计算速度，采用了简化的基于物理的（梁和板）、传感器可动部件的两自由度模型。该模型的能力和准确性通过三维有限元模拟和仪器化样品的实验结果进行了评估。结果表明，该降阶模型在系统动力学方面提供了准确的结果。为了在高冲击加速度下容易失效的区域内获得相当准确的应力场结果，通过考虑凹角引起的局部应力放大，提出了一个修正因子。
