ИСТИНА

A semi-analytic solution for predicting the evolution of damage in the process of plane strain bending under tension of a sheet of elastic-plastic, isotropic, incompressible, strain hardening material is provided. No restriction is imposed on the strain hardening law. The evolution of damage is described by an arbitrary uncoupled damage mechanics model. The final result is the dependence of the damage variable at the site of fracture initiation on any geometric parameter of the process in parametric form. Having the critical value of the damage variable it is possible to use this dependence for determining the value of the geometric parameter chosen at which the initiation of fracture occurs. An illustrative example is provided for Swift's hardening law and Cockcroft - Latham damage evolution law.