Abstract
The purpose of this paper is to investigat problems of the buckling strength and bracing spaces for beam-column by experimental analysis. This experiments include two experimental series A and B. The object of A-series is to investigate the lateral buckling strength of beam-column. In this experiment, new spherical block is used. Experimental values of buckling strength are fairly good approximation to theoretical values and the behavior of deformation is good. From experimental results, we find that the increase of post buckling strength is a little. Then, if we take notice of the strength of the members, we may take the post buckling strength into considerate at design the members. However, we can not expect the deformation capacity of the nonbrced beam-column. B-series is made experiment to explain the bracing space of beam-column from point of view of the plastic steel design. The theoretical ground of bracing space is the theory of M.G.Lay. In generally, there are two foundamental optimum condition to consider the bracing space of beam-column. 1) The attainment of the maximum in-plane moment capacity. 2) The attainment of arotation at which local buckling occurs in member. From these experimental results, we can not expect the rotation capacity after maximum in-plane moment capacity. In particular, this tendancy is remarkable in the beam-column subjected two end moments. Therefor, deciding the bracing space of beam-column, is is apropriate to adopt the first optimum condition.
