自然歪を用いた有限変形の弾塑性解析に関する研究

（大きな単純剪断の予変形後の繰り返し荷重下で得られる降伏応力について）

抄録

The yield stress under cyclic load after applying the large simple shear to the specimens is estimated based on the Natural Strain theory. As for the method of determination of yield stress in each cycle, the tangent modulus in the principal deviatoric stress and deviatoric strain curve is adopted in the present study. Then, the change of yield stress with an increase of cycle number is examined under conditions of different size of pre-deformation and the different strain amplitude of simple shear. Moreover, the experimental results obtained from this method are compared with the results from the conventional proof stress.