Modified strut and tie model of headed stud shear connectors in open trough profiled sheeting for predicting the post cracking load bearing resistance. (LAJ21.D)

Current EN 1994-1-1 provides statistically calibrated equations for predicting the strength of headed stud shear connectors in profiled steel sheeting. Recent tests showed that the design re-sistance is overestimated for some novel open trough decks. A mechanical model was developed within the RFCS Project DISCCO [3] that considers “stud in bending” component and the elastic bending resistance of the concrete rib separately (1-2 mm slip). However, to represent the behav-iour of the connector in the post-cracking stage (2-6 mm), a “Modified Strut and Tie” model was developed with the support of experimental and numerical results. The concrete and the steel deck were replaced by a system of strut and tie elements whereas the stud was considered as a beam with one or two plastic hinges. In accordance with test observations, the authors assumed that the resistance of the model is limited by the capacity of the strut in front of the stud estimated through an analogy with RC corbels. The analytical resistance of the system was finally derived and compared with the results of 193 push-out tests: the statistical evaluation delivered a corre-lation coefficient of 0.81 and a coefficient of variation of 0.15.