EXPERIMENTAL AND NUMERICAL STUDY OF THE FRAGMENTATION OF EXPANDING WARHEAD CASINGS BY USING DIFFERENT NUMERICAL CODES AND SOLUTION TECHNIQUES

摘要

We evaluate the applicability of the Johnson-Cook strength and fracture modelby comparing fracture behaviour of an expanding steel casing of a warhead withexperiments. We apply different numerical solution techniques such as Eulerian,Lagrangian, Smooth particle hydrodynamics (SPH) and the corpuscular modelsrecently implemented in IMPETUS Afea. Much of the fracture behaviour wascorrectly captured, although there were still some disagreements withexperiments. However, the fracture behaviour was improved by letting theductility decrease with strain rate, a phenomenon that may be explained as therealization of adiabatic shear bands. An implemented node splitting scheme inIMPETUS Afea seems very promising.