在考虑构件弹性小变形的机构动力学有限元分析中 ,某些构件的弹性特性对动力学过程影响很小 ,因此可以作为刚体单元来处理。该文对这种刚体单元作了详细的描述 ,建立了其质量矩阵和刚度矩阵。这种单元可以作为考虑构件弹性变形的机构动力学有限元法的单元库中的一种基本单元 ,用于模拟机构系统中的刚性构件 In the finite element analysis of mechanism dynamics which takes into account the small elastic deformation of members, the elastic properties of some members have little influence on the dynamic process and can therefore be treated as rigid body units. In this paper, a detailed description of this rigid body unit is given, and its mass matrix and stiffness matrix are established. Such a unit can be used as a basic unit in a unit library of a mechanism dynamic finite element method taking into account the elastic deformation of a member to simulate a rigid member in a mechanism system