Energy absorption and failure in aluminium alloys: An experimental and numerical study

Abstract

Aluminium alloys are a preferred group of materials for crash components in the automotive industry, often offering a substantial strength-to-weight ratio and ductility. The R&D process in the automotive industry is continuously accelerating and the utilization of and need for reliable numerical tools are ever increasing. The FractAl project aims to develop and validate numerical tools for simulation of plastic deformation and ductile fracture in 6000-series aluminium alloys. A crucial part of this work is to perform physical tests and numerical simulations of alloys by varying compositions and processing at various scales and stress states, both to extend the knowledge on the experimental behaviour and for validating and supporting modelling activities. This thesis consists of studies that aim to investigate how changes in the alloy and the materials processing affect ductile fracture and the mechanical behaviour of aluminium components as well as to perform micromechanics-based numerical simulations of such components. The thesis is divided into three parts. Part 1 studies how changes in the constituent particle content affect the mode I fracture behaviour in three different alloys. Part 2 investigates experimentally how changes in the materials processing affects the behaviour of crash components. Part 3 aims to see how solid element simulations with coupled plasticity and damage in the material model may predict the behaviour of the crash boxes from Part 2.