Force chains behaviours of Al-PTFE granular composite under elevated strain rates

Abstract

This study proposed a simulation method to characterize the influence of mesostructural force chains on the dynamic response of aluminum-polytetrafluoroethylene(Al-PTFE) granular composite under strain-controlled compression. The model was developed followed real Al particle size distribution. Based on the analysis of force chains, the global deformation, mechanical strength, and failure behaviour for the material were investigated. The results indicate that, with the increasing of strain rates, the yield strength of the Al-PTFE increases, but it is inversely proportional to the ultimate compressive strength. The stability of force chains accounts for the phenomenon that a higher strength is observed in the material under lower strain-rate impact. Particularly, an angle of force transmission is introduced to quantitatively explain the evolution mechanism of force chains.