The Analysis Of Stress-induced Phase Transformations In Elastoplastic Materials

Many studies have been devoted to the study of stress-induced phase transition, but the continuum model for it are usually based on thermoelasticity, nonlinear elasticity or hyperelasticity, which can be found in the references of Abeyaratne, Knowles, Gurtin, Morodio, Freidin and Fu. In this paper, we will provide a general study for the phase transition in elastoplastic continua.For multi-deformations in elastoplasic materials,Ericksen have worked on phase transition in elastoplastic bars and applicated Maxwell stress to it successfully. Phase transformations in elastoplastic bars are investigated for both infinitesimal deformation and finite deformation in the present work. It is verified that phase transformations can definitely occur in elastoplastic bars with strain softening behavior, the Maxwell stress and the strains inside both elastic phase and elastoplastic phase are all determined, and the manner with which the material softens exerts no influence on the occurrence of phase transformations. It is proved that for any assumed strain-softening curve the algebraic sum of areas enclosed by the Maxwell stress straight line and strain-softening cure is always equal to zero that agrees with the result give by Ericksen for the analysis of phase transformations in nonlinearly elastic bars. Numerical examples demonstrate that the jump of strain across the interface between phases is very large while the ratio of plastic tangential modulus and elastic modulus is smaller. In this case the analysis of phase transformations using infinitesimal deformation theory is also very large and it is necessary to analyze the phase transformation using the finite deformation theory. As the elastoplastic constitutive models are suitable for the most of emerging materials, the research on phase transformations in elastoplastic materials is valuable in both theory and practice.In the present paper a general analysis of kinking in elastoplastic continua is presented by modeling kinking as a stress-induced phase transformation. A physical...