High Strain Rate Response of A356/Al2O3 Aluminum Alloy MMCs Using Ls-Dyna

Abstract

Aluminum alloy Metal Matrix Composites (MMCs) have evoked a keen interest in recent times for potential applications in aerospace, defense, marine and automotive industries owing to their superior strength to weight ratio and high temperature resistance despite the higher manufacturing costs. The ability to withstand dynamic loading is an important design criteria for many structures in above applications. The Split Hopkinson Pressure Bar (SHPB) also referred to as Kolsky bar is a commonly used setup for high strain rate test in strain rate range from 102 to 104 s-1. The high strain rate data is required for safety and structural integrity assessment of structures subjected to dynamic loading. As high strain rate data is not easily available in open literature need was felt for setting up such high strain rate testing. Four distinctly different A356/Al2O3 Aluminum alloy MMCs reinforced with 0, 4, 8 and 12% fiber volume fraction of aluminum oxide (Al2O3) particles were prepared using stir casting process. These four different MMCs were numerically characterised with SHPB test setup using Ls-Dyna software. The compressive stress-strain behavior was obtained at different strain rates ranging from 100 to 1200 s-1. The high strain rate results of compressive SHPB for all specimens were obtained in the form of stress-strain graphs, which strongly indicates that the high strain rate affects on the dynamic mechanical behaviour of MMC materials. These results are helpful to select the MMCs for structural applications where materials go under dynamic loading.