Abstract
In structural analysis, the so-called multi points constraints are often used for practical boundary conditions. In order to incorporate the multi points constraints into the finite element formulation; the penalty method, the Lagrange multiplier method and the master-slave elimination method have been adopted so far. In this study, the focus is placed on the effectiveness of these methods in iterative solver. A simple contact problem is solved by these method using the multi point constraints. As results, the convergence of the penalty method with conjugate gradient method is very slow, while the Lagrange multiplier method with conjugate projected gradient method and the master-slave elimination method with conjugated gradient method, proposed in this study, show stable convergence.