随机参数刚弹耦合平面连杆的动力分析

建立考虑物理参数、几何参数及荷载均为随机变量的平面连杆机构的动力学方程,在建模中计入刚弹耦合项和运动副的粘性摩擦。利用Newmark-β逐步积分法将此随机参数机构系统的动力学方程转换为随机参数的拟静力控制方程。利用求解随机变量函数数字特征的矩法和代数综合法,导出机构动态弹性位移的均值和方差计算公式。通过算例考察了机构的杆长、截面半径、质量密度、弹性模量的随机性,刚弹耦合项和运动副摩擦对机构动力响应的影响。

Dynamic analysis for a rigid-elastic coupling linkage mechanism with random parameters

The vibration equations of a linkage mechanism with random physical and geometrical parameters under random excitation were established.considering rigid-elastic coupling and viscous friction.Its dynamic equations with random parameters were transformed into guasi-static governing equations with Newmark-β step-by-step integration method.The mean value and the variance of elastic displacement responses were calculated with the moment method and the algebra synthesis method.The influences of randomnesses of bar length,cross-section radius,mass density,elastic modulus,rigid-elastic coupling terms and viscous friction on the mechanism dynamic response were studied through an example.