Ultimate behaviour of bolted T-stubs under large displacements: A mechanical model

To provide a tool able to deliver an accurate prediction of the response of bolted T-stubs, a novel mechanical model based on a step-by-step integration algorithm is presented. It explicitly considers some complexities occurring in the large displacement range, with detailed non-linear modelling of the sources of strength and deformability. As shown by the comparison of model and test data, all the complexities considered are necessary to predict T-stubs' resistance and their ultimate displacement capacity accurately. Indeed, the accuracy of the proposed model, both in terms of ultimate displacement (δv) and maximum strength (F), is evaluated considering a set of recent test data and the predictions of a previous mechanical model, which is based on a first-order approximation of the T-stub response. Concerning the prediction of δv, the mean value of the ratio δv, th/δv, exp is equal to 0.87, with a CoV equal to 0.14. Similarly, the mean value of the ratio Fth/Fexp is equal to 0.96, with a CoV equal to 0.17.