構造用鋼材の多軸応力状態における繰返し応力-ひずみ関係 : 繰返し力を受ける鋼構造溶接接合部の破壊挙動に関する研究-第1報

抄録

In this paper, we develop and simplify the numerical plastic model that determines stress-strain relations according to the states and the magnitudes of the yielding surface and the bounding surface in stress space. We newly introduce the following matters; (1) The intermediate surface for determining the plastic strain hardening rate and the magnitude of the bounding surface, (2) The rate of expansion and contraction of the yielding surface. (3) Taking account of the effect of yielding plateau. The usefullness of this method is proved by two ways; one is to compare the calculated results with the experimental results on structural steel and weld metal for cyclic loads, the other is to compare with another method. The, parameters to define the strain hardening behavior in this method are σ_y, ε_<st>, σ^B_<in> and E^B, which are able to be determined easily by the results of monotonic tensile test. Further, using these parameters, we obtain the rate of expansion and contraction of the yielding surface (χ).