Cohesive zone method based multi particle finite element simulation of compaction densification process of Al and NaCl laminar composite powders

Abstract

Multi particle finite element method (MPFEM) has been extensively used to numerically model the compaction process of powder materials. However, MPFEM is not able to simulate the fracture phenomenon for brittle powder materials. In this study, cohesive zone method (CZM) based MPFEM is developed to simulate the compaction densification process of Al and NaCl laminar composite powders. Cohesive zone layer and initial crack are used in modeling the NaCl particle to reproduce its fracture process. A simulation of gravity effect is first conducted to arrange the powders randomly, and then top punch moves downwards to compact the laminar composite powders. Different initial random packing structures, size ratios of NaCl/Al powders and contents of NaCl powders are constructed for compaction with different pressures. Macro and micro analysis of the numerical modeling results is carried out to identify the densification process. Physical experiments and data fitting are used to validate the accuracy and robustness of the numerical simulation. Results demonstrate that the developed CZM-based MPFEM has successfully simulated the fracture phenomenon of NaCl powders and the compaction process of Al and NaCl laminar powders.