Structural behaviour of Al-Si die-castings: Experiments and numerical simulations

Axial crushing and three-point bending tests have been performed in order to establish an experimental database of the behaviour of generic high-pressure die-cast (HPDC) AI-Si alloys. The experimental data are used to obtain a validated methodology for finite element modelling of thin-walled cast components subjected to quasi-static loading. The HPDC structural components are modelled in the non-linear explicit FE-code LS-DYNA using shell elements. The behaviour of the cast aluminium alloys are described using the classical J(2) flow theory and the Cockcroft-Latham fracture criterion, which is coupled with an element erosion algorithm available in LS-DYNA. The comparison of the experimental and predicted behaviours of HPDC components gives promising results. The use of the fracture criterion of Cockcroft and Latham seems to be an effective approach to predict failure in HPDC components. A novel modelling approach is outlined accounting for different material properties through the thickness, thus incorporating the effects of a fine-grained surface layer and a central region that possesses lower ductility. (C) 2008 Elsevier Masson SAS. All rights reserved.