中文摘要：

应用修正的偶应力理论及变分原理推导带有von-Karman非线性的微简支梁的运动方程及相应的边界条件,并分析梁的宽度、高度、长度和极板间距对吸合电压的影响以及相应的尺度效应变化规律.

英文摘要：

We derived the equation of motion and corresponding boundary conditions for a simply supported microbeam with von-Karman nonlinearity by using the modified couple stress theory and the variational principle,and analyzed the influences of the width,height,length of the beam and the initial gap between the microbeam and the stationary electrode on the pull-in voltage and the change rule of corresponding scale effects.