A failure criterion based on material instability

Scaling laws for adiabatic shear bands are used to parameterize a model that is suitable for introducing shear damage within engineering calculations. One-dimensional solutions to the governing equations for a single shear band provide laws that connect the driving deformation, the imperfections, and the physical characteristics of the material to the process of stress collapse [International Journal of Plasticity 8 (1992) 583, Mechanics of Materials 17 (1994) 215]. The current model uses homogeneous material response and the scaling laws to anticipate the correct timing beyond the maximum stress at which stress collapse should occur. The model is implemented into a finite element code for wave propagation and used in the analysis of boundary value problems that are dominated by shear failure. Finally, implications of the model for simulations of material failure are discussed.