Abstract
Usually, the moment capacity of web at beam end connected to RHS column is negle cted because that web plate dose not penetrate column. But some amount of web moment are coveied to column and it depends on lateral stiffnes of column flange. Still rats hole (so called scallop) of beam web at the joint decreases deformation capacity of beam and becomes the cause of crack or collapse of beam flange. The pourpose of this paper is to point out (1) computational method of plastic moment of beam web and (2) effects of rats hole on the strength and deformation capacity of beam. For the purpose above mentioned, analytical and experimetal study were done and following conclusions were gained. (I) Evaluate equations for plastic moment of beam end were induced based on plastic yield line theory and on 4 cases those are varried the position of plastic neutral axis of beam approximate equations were induced from precise equations. Solutions by approximate equations were compaired with experimental results and showed a good agreement. (II) Experimental results of joint with rats holes and without rats holes were compaired. The results of specimens with rats hole were collapsed at flange under 2〜3 cyclic laoding but on specimen without rats hole, collapse of flange did not occur and strength were about 10 % over those of specimen with rats hole.
