Numerical simulation of fracture behavior under high-velocity impact for Aluminium alloy 6060 target plate

Abstract

Impact studies are always important, challenging and are performed to ensure that materials do not fail catastrophically when subjected to high-velocity impact. Many a time, the material subjected to impact at high velocity, leads to fracture. The present investigation demonstrates the fracture behavior of the ductile target material under the high-velocity normal impact of a flat-faced circular rigid projectile. The analysis is a large deformation dynamic elastic-plastic problem at high velocity and is analyzed using an in-house finite element code developed on MATLAB. The rectangular target material is Aluminum Alloy 6060 of 1 mm thickness. The contact constraints are applied using Lagrangian formulation. The fracture of the flat target plate under high-velocity impact demonstrates complex self-contact conditions. In the present work, a comparison is also made between the Lagrangian formulation and Augmented Lagrangian formulation for the analysis of the residual velocity of the projectile and fracture behavior of the ductile target material. The results demonstrate that there is minimal difference in the residual velocity of the projectile due to both the above formulation, but the fracture behavior of the ductile target material was different showing a small difference in the number of failed elements at some time steps. It is found that at lower velocity ranges, the fracture is of localized-type whereas, at higher values of the projectile velocity, the fracture behavior in 6060 alloys is of diffuse-type in nature.