THE PARAMETRIC VARIATIONAL PRINCIPLE AND FINITE ELEMENT METHOD FOR MATERIAL WITH DIFFERENT MODULUS IN TENSION AND COMPRESSION

The parametric variational principle is established for the static problem with different modulus in tension and compression. Based on the parametric variational principle and finite element method, the 2-D bimodular static problem is transformed into a linear complementarity problem that can be solved by using Lemke’s algorithm. The method doesn’t need the pre-assumption of the stress state and the update of the stiffness matrix. Numerical examples show that the proposed method is stable and significantly accelerates the convergence of solution.