Initial Elastic Stiffness of Bolted Shear Connectors in Steel-Concrete Composite Structures

Chenggong Wang,Diankai Cao,Xiaoyang Liu,Wenzhuo Liu,Yucai Jing,Guotao Yang,Chao Hou

doi:10.1155/2022/7008727

Abstract

Bolted shear connectors have the advantages of being easily fitted and dismantled during construction, the initial elastic stiffness of which has a great influence on the structural performance of the connected composite structures. In this paper, the initial elastic behaviors of three types of bolted shear connectors used in steel-concrete composite structures (i.e., the bolt with nonembedded nut, the bolt with single-embedded nut, and the bolt with double-embedded nuts) are investigated using finite element analysis (FEA). After the FE models are verified against the experimental results in other literature, an extensive parametric study is carried out to investigate the effects of eight parameters of the composite structures on the initial shear stiffness and tension stiffness as well as coupling stiffness. Empirical formulas are subsequently developed for obtaining the initial elastic stiffness of the bolted shear connectors, based on which further FEA is performed. The FEA results are in good agreement with the experimental results, illustrating the effectiveness of the empirical formulas.

Highlights

Steel-concrete composite structures have been widely used in civil engineering for decades because of their outstanding mechanical performances such as high strength and stiffness, strong resistance to impact and seismic loading, and ease of construction, combing the advantages of both component materials
Various types of connectors that can enhance the composite action in the composite structures have been proposed, such as stud connectors, rebar connectors, and profiled connectors [1,2,3,4,5]
In the works of Pavlovicet al. [17, 18], comparisons between the bolts with singleembedded nut [Figure 1(b)] and headed studs were analyzed to better understand the failure mode of these connectors, the results showed that the bolted shear connectors were similar to headed studs in terms of shear resistance but the bolts are prone to brittle failure

Summary

Introduction

Steel-concrete composite structures have been widely used in civil engineering for decades because of their outstanding mechanical performances such as high strength and stiffness, strong resistance to impact and seismic loading, and ease of construction, combing the advantages of both component materials. Liu et al [21] and Chen et al [22] examined the structural behaviors of double-nut bolts [Figure 1(a)] in the prefabricated steel-concrete composite beams, considering the effects of bolt diameters and constraint conditions of the reserved holes. In the work of Liu et al [48], the behaviors of high-strength friction-grip bolts in steel-concrete composite beams were studied using a three-dimensional FE model. Because of the symmetry of the structure, only one-quarter of the specimen composed of the bolt, nut, steel beam, base plate, concrete slab, and reinforcing bar is modeled [see Figure 3(a)]. Erefore, the embedded nut in composite structures affects the stiffness of the bolts

Parametric Study

Empirical Equations

Findings

Applications