CONSTITUTIVE RELATION OF ELASTOVISCOPLASTIC POROUS MEDIA SUBJECTED TO SHOCK--PART I:STATE EQUATION
弹粘塑性孔隙介质在冲击荷载作用下的一种本构关系--第一部分:状态方程

The process of deformation and fracture of deformable solid media subjected to shock is accompanied by many irreversible dissipative mechanical,physical and chemical processes,and the constitutive equations of solid subjected to shock should express these irreversible features. The mechanical behaviors of elastoviscoplastic porous media subjected to hydrostatic shock are studied here in the framework of irreversible thermodynamics of elastoviscoplastic media. The corresponding constitutive equations are expressed by Helmholtz free energy of Debye form,as it is more rational for solid. The influence of porosity on the mechanical behaviors of elastoviscoplastic porous media subjected to hydrostatic shock is remarkable,and here it is considered by means of effective strain method. The evolution equation of porosity is also obtained on this basis. The constitutive equations presented here are relatively simple,and their physical meaning is clear,corresponding to irreversible thermodynamics. In order to validate the proposed constitutive relations,a numerical example is given,and the agreement is good with the existing results.