繰返し荷重をうける鉄骨断面の弾塑性解折に関する研究 : (第 1 報)(断面の曲率変化について)

Abstract

This report presents the elasto-plastic analysis of of stress or strain distribution in steel section. subjected to alternative load (axial force and bending morment). This theory based on the following assumptions 1) Assuming thal steel is perfectly elasto-plastic solid, and the Bauschinger effect, strain-hardening are ignored. 2) After deformation, the cross section remained plane. The method of this analysis are following 1) When the axial force and bending morment increased to P_O, M_O, and then decrease to P, M. Now the unloading load (P_N, M_N) are M_N=M_O-M P_N=P_O-P 2) The elastic region of unloading load (P_N, M_N) are determined geometricaly, using stress distribution of initial load (P_O, M_O). 3) As the strain distribution of the unloading load (P_N, M_N) is linear, the stress distribution is linear too, in theelastic region of unloading load. Then we get the stress distribution of the unloading load, using equilibrium of load and stress. And then strain distribution of bending curvature are determined. 4) We can get the stress distribution of any unloading state by superpasing the result of 3) on the initial distribution. Strain distribution, Bending courvature are also like so on.