GOALI: High-strain Rate Deformation and Failure of Magnesium Alloys

University Of Florida, Gainesville FL

Investigators

Abstract

This Grant Opportunity for Academic Liaison with Industry (GOALI) provides funding for the development and validation of a novel computational tool for modeling high-rate deformation and failure of magnesium alloys. A multi-scale approach will be used for describing the effects of grain level deformation mechanisms on damage and failure at a structural level. The framework that will be used is that of polycrystalline plasticity and non-linear homogenization. Focus will be on the improved modeling of the plastic properties specific to magnesium alloys, namely tension-compression asymmetry associated to twinning, anisotropy, and its evolution with increasing strain rate. In partnership with General Motors, a multi-scale experimental verification and validation of the new theory for both quasi-static and dynamic regimes will be conducted by performing material characterization, fracture tests, and crush tests over a range of loadings and strain rates, as well as gathering micro-structural information at key stages of the fracture process. If successful, the results of this research will address important strategic needs of the US automotive industry for increased use of lightweight materials such as magnesium alloys in body structures. Environmental benefits are also anticipated through increased fuel-efficiency associated with the reduction in weight of the transportation vehicles. The application of the models will allow the designer to assess the behavior of a given alloy during the finite element analysis phase of the design process. Furthermore, it will allow numerical testing of the performance of components in crash situations both in terms of energy absorption and ability to retain structural integrity, with direct impact on the safety, quality, and environmental friendliness of the cars of the future.