Finite Element Method Used in the Multibody Systems With Elastic Elements

In many cases when a study of multi-bodies systems is performed, the hypothesis of rigid elements is considered. Actually the elasticity of the components of the system can be large enough, so that the dynamic response can be not only quantitative but also qualitative different. For this reason, in some applications, particularly in the field of robotics and high-speed vehicles, is necessary to consider the elasticity of elements and to use correspondent models. To study such system with the classic mechanics theorems is not a practical way because the motion equations have, generally, no analytical solutions. For this reason, it is necessary to use numerical methods and the finite element methods (FEM) remains one of the most important tool. The considerations included in the present papers may be used both for the analysis as well as for the synthesis of any kind of plane mechanism, (particularly made by pinned bars linkages). An analysis of the integration methods for such multibody system is performed and the properties of the motion equations are also presented.