EXPERIMENTAL STUDY ON DEFORMATION CAPACITY OF COMPOSITE BEAMS WITH CONVENTIONAL TYPE BEAM-TO-COLUMN CONNECTIONS : Evaluation of earthquake resistance of steel moment frames considering deformation capacity of composite beams Part 1

Abstract

Many fractures in beam-to-column connections of steel framed structures occurred in Hyogo-ken Nanbu Earthquake. In this paper, we notice on the influence of composite beams as a factor of such fractures, and investigate the deformation capacity of composite beams by a series of experiment. Main conclusions are as follows. (1) The deformation capacity of composite beams is remarkably lower than steel beams without slabs. (2) Section properties and loading histories have little influence on the deformation capacity of composite beams. (3) When composite beams are subjected to a positive bending moment, following phenomena are observed : a) Strain is concentrated to lower flanges. b) Plastic deformation is concentrated to narrow area near the beam-to-column connections. These are the factors which reduce the deformation capacity of composite beams.