Micromechanics of localized fracture in inelastic solids under dynamic loading processes

The main objective of the paper is the investigation of adiabatic shear band localized fracture phenomenon in inelastic solids during dynamic loading processes. This kind of fracture can occur as a result of an adiabatic shear band localization generally attributed to a plastic instability implied by microdamage and thermal softening during dynamic plastic flow processes. The theory of thermoviscoplasticity is developed within a framework of the rate type covariance material structure with finite set of internal state variables. The relaxation time is used as a regularization parameter. The viscoplastic regularization procedure assures the unconditionally stable integration algorithm by using the finite element method. Utilizing the finite element method and ABAQUS system for regularized elasto-viscoplastic model the numerical investigation of the three dimensional dynamic adiabatic deformation in particular body at nominal strain rates ranging 10(3) - 10(4) s(-1) is presented. A thin shear band region of finite width which undergoes significant deformations and temperature rise has been determined. Its evolution until occurrence of final fracture has been simulated. Numerical results are compared with available experimental observation data.