鉄骨部材の3次元弾塑性挙動に関する実験的研究 : その1.定軸圧下での弾塑性ねじり挙動(I)

抄録

The behavior of the intermedicate steel beam-columns subjected to torsion combined with constant axial load was studied experimentally. Eleven specimens were tested with different combinations of the cross-sectional shapes and the axial force ration. The results of the experiment and the analysis may be summarized as follows : (1) The specimens of thin-walled open section under the high axial force ratio failed due to the formation of a collapse mechanism and those under the low axial force ratio did not fail as a result of the strain-hardening and the helix effect. Further, the specimens of thin-walled closed section failed due to local bucling. (2) The maximum torque is affected by the axial force ration. (3) The ductility factor is affected by the cross-sectional type and the axial force ratio. (4) The band-plate increases the elastic stiffness and the yield torque. (5) The inelastic torsional behavior can be conservatively estimated based on the plastic hinge method.