Effect of restraint for continuous braces on lateral buckling load for h-shaped beams with warping restraint of beams to column joint

In Japanese moment resisting steel frames, H-shaped beams are rigidly connected to the box sectional columns which have high warping restraint against lateral buckling deformation of beams subjected to flexural moment. On the other hand, most of beams in frames are connected with continuous braces such as roof purlin or concrete slab which are effective to prevent the lateral buckling of beams. In this paper, the equation of the elastic lateral buckling load for H-shaped beams with warping restraint and continuous braces are developed. Elasto-plastic lateral buckling stresses of the beams and lateral stiffing force and rotational stiffing moment of continuous braces are evaluated by the energy method and numerical analyses.