Multi-body finite element method for contact problems in hydraulic structure

Multi-body finite element method (MFEM) is proposed for analysis of local contact problems in hydraulic structure. Based on the block theory of discontinuous deformation analysis (DDA) method, each block can move and deform independently, and blocks contact with each other on their boundary. Each single block is analyzed using the finite element method (FEM) in the corresponding local coordinate system, and all contacting blocks need to satisfy the displacement compatibility requirements between two blocks. In this way, MFEM assures the continuity of the displacement and stress state between blocks. The calculated results of this method are in fairly good agreement with the actual situations. Normal and tangential stiffnesses are not required in algorithm, and thus the overlap problem is successfully avoided. Moreover, the accuracy of the block internal deformation is effectively improved. The theoretical basis and finite element coordinate equations for the proposed method are obtained. Finally, the validity and accuracy of the proposed procedure are demonstrated through three numerical examples.