This paper describes the estimation-method for the shape of yield surface generated after applying the large pre-deformation. In a series of our previous reports, using a test piece applying the large pre-deformation of combined loading of tension and shear, the shape of yield surface has been estimated based on the Natural Strain theory by investigating the tangent modulus of the deviatoric stress-deviatoric strain curve, which is obtained by performing the experiments of proportional loading tests of tension and torsion. Since the shape of the yield surface becomes convex in the direction of the pre-deformation, the existence of anisotropy in yield surface has been confirmed from the results of our previous experiments. In this paper, another type of pre-deformation is chosen as the subject of this study. In particular, the deformation history of uni-axial tension after simple shear is examined in this report.
