改良形J2DとしてのMG構成式の簡易化と大変形弾塑性FEM解析などによる検討

抄録

Large elastic-plastic deformation in, for example, metal working processes has been analyzed so far primarily on the basis of J 2 D, especially when the strain localization such as shear-band formation would take place in the material. However, J 2 D includes some ambiguity in loading-unloading judgement. The MG-constitutive equation was previously proposed by the author to recover such faults of J 2 D. MG c. e. has a difficulty such that it leads a nonlinear stiffness equation in the finite element method (FEM) . In this paper, two revised forms of MG c. e. are proposed which are readily introduced into the existing computer programs of FEM based on J 2 D or J 2 F. It is demonstrated by some basic large deformation analyses that the revised MG c. e. 's give very similar results as those based on the original MG c. e. or to each other.