自然歪理論に基づく大きな単純剪断変形下の降伏曲面の形状

（逆剪断の予変形量と降伏曲面の異方性の発達の関係について）

抄録

This paper describes the anisotropy of yield surface, which is formed during a large pre-deformation. In a series of our previous studies, the shape of yield surface when the simple shear in the reverse direction is applied after the large simple shear in the forward direction have been examined. Since the anisotropy arises on the reverse shear side, it is revealed that the anisotropy is newly formed during process of the reverse shear. In the present study, in order to investigate the intermediate status of the development of anisotropy, the experiments are conducted with the small reverse shear condition as compared with the previous experimental condition. Then, the shape of yield surface estimated in this study is compared with the result in our previous report.