具有不对称弹性梁的梳状微加速度计的结构变形分析

Structure deformation analysis of comb microaccelerometer with asymmetrical elastic beams

通常情况,梳状微加速度计具有对称结构。但是加工工艺的缺陷可能导致梳状微加速度计的弹性梁不对称,引起结构发生扭转运动。对于双端固定梁式结构,分析了弹性梁的不对称性对结构等效刚度的影响。在假设弹性梁长度相等,但弯曲刚度不相等的前提下,推导出了结构的等效刚度计算公式,并将其推广到任意不对称情况。最后用有限元仿真实例验证了理论计算公式的正确性。所采用的分析方法可以运用于其他具有不对称弹性梁的MEMS结构的变形分析及其误差灵敏度分析中。

Usually, Comb Microaccelerometers have symmetrical structure. However, imperfect fabrication may make the elastic beams of comb microaccelerometer strcucture asymmetrical, and cause rotation of the structure. For the structure with double-clamped beams, the paper analyze the effect of the asymmetry to the effective stiffness .On the assumption of equal length and unequal bending rigidity, the explicit formulas to calculate the values of effective stiffness are obtained, and we extend the formulas to usual asymmetrical case. The correctness of formula for effective stiffness is checked by the finite element method. For the other meres structures with asymmetrical elastic beams and its error sensitivity analysis, the analysis method in this paper can be used for them.