Experimental Investigation and Finite Element Analysis for Mechanical Behavior of Steel-concrete Composite Beams under Negative Bending

Abstract

Experiments on four steel-concrete composite beams under negative bending were carried out in this paper. The effects of three factors such as bending moment ratio between two ends of a beam, height-to-thickness ratio of web, lateral slenderness ratio of compressive flanges on the bending bearing capacity Mu of composite beams were investigated. The experimental results indicate that Mu and Mu/Mp decrease as bending moment ratio between two ends of a beam increases, and Mp is cross-section plastic moment of composite beam. Mu is less affected by height- to-thickness ratio of web. However, Mu/Mp decreases as height-to-thickness ratio of web increases. If lateral slenderness ratio of compressive flanges is large, Mu and Mu/Mp are less affected by lateral slenderness ratio of compressive flanges. Finally, the finite element models of four composite beams under negative bending were established. The calculated results agree well with the experimental results.