抄録
In order to understand the overall shape of the yield surfaces (rigorously defined as the loading surfaces or offset yield surfaces) of prestrained metals, the shapes of various intersections of several planes and cones with yield surfaces are investigated. The yield strength at each intersection is evaluated along the angle which is measured from the prestrained direction in the stress space. Though the data obtained from the experimental results were unrelated, the trends of yield strength are similar with each other. The similarity is especially excellent in the case of the uniaxially prestrained mild steel. This fact suggests that the yield surfaces of prestrained metals have the shape of the rotational symmetry, with the rotational axis in the prestrained direction.