Abstract: Free-Lagrange Method is a new attempt to simulate two dimensional compressible flow with large distortion. It gives up the restraint usually required in traditional Lagrangian method to make fixed connectivity among cells. In FLM the neighbor relation among notes is tested and revised in each cycle, therefore adapti flow distortion naturally. In addition we have made special treatments for free surfaces and interfaces. The application of FLM to hydro-elastic-plastic flow proves to be satisfactory.

Key words: free-lagrange methods, slide lines, neighbor-relation adjustment, Voronio mesh, penetration test