A multi-parameter method for static behaviour of headed stud with ductile fracture in push-off tests

Purpose The purpose of this study is to investigate the effects of stud height, stud diameter, ultimate stress of stud and concrete strength on the static behaviour of studs in push-off tests based on the ductile fracture theory. Design/methodology/approach Push-off tests of headed stud shear connectors with different heights and diameters used in concrete of various strengths were designed and implemented. A finite element model was established based on a ductile fracture criterion of ML15 cold-heading steel with stress triaxiality and Lode angle parameter. Based on the results of the parametric study of the numerical model, equations were proposed to evaluate the effect of stud height h s , stud area A s , concrete strength f c and stud ultimate strength f su used in concrete of various strengths on the static behaviour of studs. Findings The typical failure phenomenon observed among the test specimens was the fracture of the shank of studs. The microscopic images of the stud fracture surfaces and the verified finite element model indicate that the studs were fractured as a result of the combined action of tension and shear. Originality/value A new method for calculating ultimate load P u and ultimate slip S u is proposed in this paper. In the method, P u is linearly related to f su 0.2143 , A s 0.7790 , h s 0.0974 , f c 0.2065 . S u is linearly related to f su 1.078 , A s 0.4681 , h s (−0.3135) , f c (−0.3480) .