3-RRR平面柔性并联机构动力学分析

针对柔性并联机构动力学模型时变、刚-柔耦合、非线性的特点,以3-RRR平面柔性并联机构为研究对象,建立了一种基于有限元法、浮点坐标系和KED法的机构弹性动力学方程。首先,运用有限元法的理论,将机构的柔性杆件划分为一系列离散的梁单元模型,建立梁单元的动力学方程。然后,运用KED法,得到机构的约束关系式和装配关系式,从而得到机构在浮点坐标系下的弹性动力学方程。最后,分别对采用简化KED法和这里方法建立的机构动力学模型进行仿真分析,对比机构动平台的弹性位移/转角曲线和最大应力曲线,验证了这里建模方法的有效性。

Dynamic Analysis of 3-RRR Planar Flexible Parallel Mechanism

The dynamic model of flexible parallel mechanism has the characteristics of time varying,rigid flexible coupling and nonlinearity.Floating point coordinate system and KED method,a kind of 3-RRR planar flexible parallel mechanism’s elastic dynamic equation is established based on the theory of finite element method.Firstly,based on the theory of finite element method,the flexible member is divided into a series of discrete beam element model and the dynamic equation of beam element is established.Secondly,by using the KED method,the constraint relation and the assembly relation of the mechanism are obtained.Thus,the elastic dynamic equation of the mechanism in floating point coordinate system is obtained.Finally,the dynamic model of the mechanism are respectively simulated and analyzed by using the simplified KED method and the method in this paper,we compare the elastic displacement/rotation curve and the maximum stress curve,and the validity of the modeling method is further verified.