QUASI-FLOW THEORY OF ELASTIC PLASTIC FINITE DEFORMATION
弹塑性有限变形的拟流动理论

A Quasi-Flow Theory of elastic plastic finite deformation is proposed. Thetheory originates from the classical normality law. By introducing a weak function withrespect to elastic modulus into the constitutive equations and by improving the commondecomposition scheme of elastic and plaistic strain rates, the Quasi-Flow Theory achieves asmooth and continuous transition from the fiuite deformation Prandtl-Reuss equation (J2F)based on the norrnality law to the rate form of the hypoelastic J2 deformation theory(J2D)baised on the non-normality law.In addition, the theory can be applied to the theoret icalanalysis and the numerical simulatio n of anisotropic metals from initial and subsequentplastic deformation up to localized shear fracture. Under special conditions,the J2F,theJ2D and the const it utivetheories described by arbitrary anisotropic yield funct ions andbalsed on the normality law can be included into the Quasi-Flow Theory. This t heory hasbeen introduced into the numerical simulation of the instability and the localized deformationof ductile metaIs under plane stress/strain tension. By comparing with theoretical analysisand experimental observation,the results demonstrate the usefulness of the theory