UNDERSTANDING STRENGTH OF POWDER COMPACTS USING A DETAILED MULTI-SCALE SIMULATION

摘要

Multi-particle finite element (MPFEM) simulations, which combine the concepts of discrete elements with finite elements, are used to compress, unload, and reload a collection of 400 cohesionless and cohesive particles. The use of finite element discretization of individual particles allows for large contact deformation and the ability to simulate compaction to high relative densities. Compaction strain paths ranged from isostatic to high shear. Individual particles were treated as elasto-plastic witl E:σ_y=100. It is shown that the microstructure and the strength of a powder compact depends strongly on the strain/stress history during compaction. Our simulations show that the dependence on the strain history is conceptually similar but less pronounced than the predictions of Fleck's micromechanical model.