An One-Dimensional Phase Transition Constitutive Model

Defects are always existing in real materials, which cause stress concentration. When phase transition takes place, new phase nuclei form first at the positions of defects and then grow via phase boundary propagation. There is a certain relationship between the propagation velocity of phase boundary and the driving force, i.e. the Gibbs free energy difference between two phases. From this point, we have studied the phase transition process of real material with a model of rod containing defects, and have derive a rate-dependent phase transition constitutive relation which in form is similar to generalized Maxwell model. Based on this model, stress profiles of CdS transformation under shock loading were calculated. Results show that our constitutive model can describe the main characteristics of the experimental phenomenon, except the large stress relaxation after the precursor. The calculated were profiles are quite close to those of Fe and InSb, which suggests this model can be applicable to materials other than CdS.