A VARIATIONAL PRINCIPLE FOR CONSTRUCTING THE EQUATIONS OF ELASTOPLASTICITY FOR FINITE DEFORMATIONS

A variational principle of maximum dissipation of mechanical energy is proposed for constructing the governing equations of elastoplastic fl ow for finite deformations, based on the assumption that part of the d issipation is due to a change in the tenser of the internal variables. The required equations are obtained for the isothermal process by usi ng a previously proposed subdivision of the complete metric tenser int o elastic and plastic parts (but without invoking the idea of the rate of plastic deformation). The system of differential equations include s the equations for the tenser of the internal variables.