ON HYPERELASTIC CONDITION OF RATE-FORM ELASTICPLASTIC CONSTITUTIVE LAW AT FINITE DEFORMATION

It is proved that if the objective stress rate is taken as the Oldroyd rate of the Kirchhoff stress tensor, the integrability condition of the rate-form elastic constitutive law is λ=0, provided that the Lame parameters λ and μ are. constants. This fact renders the rate-form elastic-plastic constitutive law incompatible with the hyperelastic framework in the regime of finite deformation. Several particular situations in which the rate-form elastic con-stitutive laws can be approximately applied to the case ...