Behavior of truss connectors in composite walls subjected to cyclic loading

Abstract

Connectors are used in composite walls to transfer shear load and enhance composite action between steel plates and concrete core. The behavior of connectors was mostly obtained from push-out tests. However, connectors may suffer from failure caused by earthquake, and shear capacity is significantly reduced due to the accumulated damage subjected to cyclic loading. In this research, results of tests on seventeen truss connectors under cyclic loading, finite element modelling, and theoretical analysis on shear capacity were presented. The effects of eight variables, including weld leg size, weld length, grade and thickness of angle steel, diameter of rebar, concrete thickness, truss orientation, and number of truss connector, on the shear behavior were evaluated. Finite element modelling was undertaken and the accuracy of the established models was validated against the test results in terms of failure modes, hysteresis loops, and shear capacity. Based on force transfer mechanism and parametric study, the formula to predict shear capacity was proposed and the shear-slip model was developed. The proposed model agreed well with test data and finite element results.