Incrementally objective implicit integration of hypoelastic-viscoplastic constitutive equations based on the mechanical threshold strength model

The present paper focuses on the development of a fully implicit, incrementally objective integration algorithm for a hypoelastic formulation of J2-viscoplasticity, which employs the mechanical threshold strengthmodel to compute the material's flow stress, taking into account its dependence on strain rate and temperature. Heat generation due to highrate viscoplastic deformation is accounted for, assuming adiabatic conditions. The implementation of the algorithm is discussed, and its performance is assessed in the contexts of implicit and explicit dynamic finite element analysis,with the aid of example problems involving a wide range of loading rates. Computational results are compared to experimental data, showing very good agreement. © Springer-Verlag Berlin Heidelberg 2013.