Modeling of as-cast A356 for coupled explicit finite element analysis

Abstract

Design tools to simulate the manufacturing processes applied to aluminum components require computationally efficient finite element methods. While static processes such as casting employ implicit techniques, dynamic processes such as forging may only be modeled with explicitly. A commonplace practice to expedite explicit simulations is to employ time or mass scaling, which can lead to unexpected thermal-mechanical behaviour in coupled analyses. In both cases, the development of fully coupled thermo-mechanical simulations necessitates the use of a constitutive model that is capable of defining the flow stress as a function of temperature, strain, and strain rate. In this work, a material model for as-cast A356 is presented and applied in a range of fully coupled deformation models. Implicit and unscaled explicit models will be compared to explicit models with large amounts of scaling. Strategies for applying a material model to minimize error and maximize computational effort are discussed.