DYMAT 2009
Volume 2, 2009
DYMAT 2009 - 9th International Conference on the Mechanical and Physical Behaviour of Materials under Dynamic Loading
Page(s) 1303 - 1309
Section Constitutive Modeling
Published online 15 September 2009
DYMAT 2009 (2009) 1303-1309
DOI: 10.1051/dymat/2009184

Flow and failure behaviour of materials at high strain rates

E. El-Magd

Aachen University, 52056 Aachen, Germany

Published online: 15 September 2009

Strain hardening functions based on microstructure mechanical models are presented, which allow an accurate description of the flow curve over a wide range of strain. The influence of strain rate on the flow stress is described by functions that account for a continuous transition form the mechanism of thermal activated glide to the viscous damping mechanism. Different failure criteria are considered for dynamic multi-axial loading. Plastic instability promotes the deformation localisation and may lead to adiabatic shear banding. The debonding and fracture coarse precipitates lead to the initiation of micro-voids and micro-cracks and cause a stress drop at relatively small strains. Ductile fracture starts usually by initiation, growth and coalescence of voids. In the case of dominance of shear stresses, shear fracture is considered as an additional failure criterion.

© EDP Sciences 2009