Behavior of shear connection in web-embedded U-shaped steel-concrete composite beams: Experimental and numerical study

This paper presents a study on the longitudinal shear connection of a web-embedded U-shaped steel-concrete composite beam (WUSCCB). A push-out test of nine specimens was conducted, and a longitudinal shear bearing mechanism of WUSCCB flange-web interface was proposed. Different from conventional steel-concrete composite beams, the longitudinal shear force at WUSCCB flange-web interface is contributed by both the local compression between shear connectors and surrounding concrete and the longitudinal shear of concrete flange. A finite element analysis was also conducted, revealing the shear mechanism of embedded shear connectors. Subsequently, a parametric analysis including 39 models was carried out to investigate the effects of concrete strength and connector details on the shear resistance behavior, revealing that the width and thickness of connectors are the crucial factors of shear capacity. Based on the test and parametric analysis results, a shear connection design method is proposed. Finally, a finite element model of WUSCCB was developed to verify the design method by examining the relationship between WUSCCB flexural behavior and shear connection degree.