Tensile Behavior of Truss Connectors in Double-Skin Composite Walls

Double-skin composite walls are widely used in high-rise buildings. Connectors are used to transfer shear loads between steel plates and the infilled concrete, enabling composite action between the two materials. However, the connectors may also be subjected to significant tensile forces when the steel plates tend to separate from the concrete under compression, bending, blast load, impact load, or out-of-plane shear. Therefore, it is necessary to evaluate the behavior of connectors in composite walls subjected to tensile loading. This paper presents experimental results, numerical simulations, and theoretical analysis on the tensile behavior of truss connectors. Twelve specimens were designed and tested to evaluate the effects of weld arrangement, rebar diameter and bending angle, presence of concrete, and truss type on the tensile behavior of truss connectors. Refined finite element models, which accounted for ductile and shear damage in steel and concrete crushing, were developed, and their accuracy was validated against the test results. A method for determining the tensile capacity of truss connectors was proposed, along with a simplified trilinear model for the tensile load-displacement relationship. The research presented in this paper provides a fundamental understanding of the tensile behavior of truss connectors, which can assist civil engineers in design and promote the application of truss connectors in double-skin composite walls.