SPH Modelling of Fragmentation of Explosively Driven Metallic Cylinders

R. Vignjevic

Applied Mechanics and Astronautics Department,Cranfield University, MK43 0AL, UK, v.rade@cranfield.ac.uk

T. De Vuyst

Applied Mechanics and Astronautics Department,Cranfield University, MK43 0AL, UK

Abstract:  Meshless methods, such as Smoothed Particle Hydrodynamics (SPH), are of particular interest for the accurate prediction of fragmentation and fracture at high strain rate in metals. This paper describes an attempt of predictive modelling of progressive damage and fragmentation in explosively driven metal cylinders within a meshless framework. The approach allows for damage initiation, damage propagation including bifurcation of cracks which leads to fragmentation. It also allows the explosive material to flow between the new free surfaces and drive the crack growth.

The specific technique for representing damage used in this work was based on reduction of particle to particle effective interaction area.  Critical damage or fracture results in the interaction area being set to zero [9] and the properties of the particles were modified to allow a new free surface to form. This modelling approach was validated against the Mock-Holt experiment [6] and following the validation used to analyse fragmentation of Mk 82 bomb.