Finite Element Analysis For Structures With Rigid-body Displacements

In engineering structures, geometrically nonlinear problems have always been hot issues of engineering and academic circles of home and abroad. It is difficult to analyze some structures with rigid-body displacements such as the crawler cranes using the general finite element method, because of the geometrical nonlinearity being induced by the rigid-body displacements. So it is necessary to find an analysis method considering both the elastic displacements and rigid-body displacements of structures.In this dissertation, some basic research about the finite element analysis for structure with rigid-body displacements is studied.According to the characteristics of the structure with rigid-body displacements, the preliminary research of coupling problem on mechanism and structure by using finite element method is carried on. The geometric non-linear effect this kind of structures is also discussed. The main issues include:1. The characteristics of the structures with rigid-body displacements is analyzed, and the analysis method to this type of structure is studied.2. The equilibrium equation of the ordinary structure is achieved by using the method of calculating the nodal internal forces through establishing body-fixed coordinate system.3. Solution efficiency of the equilibrium equation of this kind of complex structures is improved by using substructure method.4. The method in this dissertation is confirmed by some examples.