Effect of warping restraint of beams to column joint on lateral buckling behavior for H-shaped beams with continuous braces under gradient flexural moment

When a steel moment frame is subjected to seismic force, H-shaped beams carry the gradient flexural moment. In Japanese steel moment resisting frames, H-shaped beams are rigidly connected to the box sectional columns, which have high warping restraint against lateral buckling deformation of beams. On the other hand, it is effective for continuous braces to prevent the lateral bucking. In this paper, the lateral buckling behavior for H-shaped beams with warping restraint and continuous braces under gradient flexural moment is clarified and elasto-plastic buckling stresses of beams and lateral stiffing force and rotational stiffing moment of continuous braces are evaluated.