A CONSTITUTIVE LAW FOR A CLASS OF 2-PHASE MATERIALS WITH EXPERIMENTAL-VERIFICATION

A constitutive equation is developed to describe the mechanical behavi our of a class of two-phase materials with locking-in inter-phase resi dual stress capability. The irreversible deformation of the materials is separated into the plastic deformation of the soft-phase and the el astic-plastic deformation of the hard-phase, which are described, resp ectively, with the corresponding divisions in a thermomechanically con sistent constitutive model. The developed constitutive equation can de scribe the main characteristics of the two-phase materials, and is ide ntical to the endochronic constitutive equation if the introduced seco ndary internal variables are ignored, and can also encompass the model proposed by Bower et al. as a special case. The validity of the prese nt model is verified by the comparison between the theoretical and exp erimental results of OFHC and the rail steel BS11.