High-velocity nonlinear deformation and collapse of a damaged medium with initial stresses

Taking into account the degradation of the properties of materials, an analysis of the nonlinear processes of deformation and fracture in a preloaded three-dimensional body with a sharp concentrator in the zone of a dissimilar joint under impact was performed. A generalized mathematical model of nonlinear interrelated deformation and destruction of damaged polycrystalline media subjected to time-varying thermomechanical influences is presented. The strong nonlinearity of the model is due to large (finite) strains and the strain-rate dependent behavior of media with a variable microstructure. Taking into account the anisotropic hardening of media and the Bauschinger effect, the corresponding nonlinear boundary value problems are formulated and their solutions are obtained using efficient numerical methods. The viscosity of the medium and second-order gradients from the internal variables of the system were used as regulators of the correctness of the problem statement. Experimental data were used to test the model. Simulation results presented.