Abstract

Topics: Constitutive model – Orthotropic Elasticity, Plasticity and Damage; SPH representation of damage; Mock-Holt experiment In order to accurately predict explosively driven fragmentation of metals it is necessary to have a good constitutive model and spatial discretisation technique which is capable of representing this process. This presentation describes on-going research on the development of a constitutive model for metals and the Total Lagrangian smooth particle hydrodynamics (TL-SPH) method and their application to modelling of fragmentation of metallic rings and cylinders. The presented outlines the main aspects of the new material model for orthotropic metals and the approach to representing damage in TL-SPH developed at Cranfield. The use of this formulation has the advantage of eliminating two drawbacks of the traditional SPH formulation with an Eulerian interpolation kernel: tensile instability and numerical fracture. Numerical examples used to validate the developments include Mock Holt experiment (shown in Figure 1) and fragmentation of metallic cylinders with more complex geometry. The modelling approach was able to reproduce the sizes and numbers of fragments observed in the experiments.