Abstract: Based on micromechanics, thermodynamics and microscale t→m transformation mechanism considerations, amicromechanics constitutive model which takes into account both the dilatation and shear effects of the transformation is proposed to describe the macroscopic plastic behavior of structure ceramics during forward transformation under different temperatures. Under some basic assumptions, the analytic expressions of the Helmholtz and complementary free energy of the constitutive element is derived in a self-co...