Tensile behavior of cruciform stubs with staggered bolt patterns

Welding stiffeners to angles improves the initial rotational stiffness and resistance of top-and-seat angle connections, but the unintended side effect is lower ductility. To balance ductility and resistance, a novel large angle connection has just been designed. As a result, there is an urgent need to test the behavior and perform theoretical research. Six cruciform stubs were designed and tested with monotonic load to reveal the plastic development of such connections. The comparison with parallel bolt patterns proved that the staggered bolt pattern could improve the ductility factor from 6.06 to 14.17 without lowering resistance. Furthermore, finite element models were used to investigate the development of bolt force. Finally, a modified method for predicting plastic resistance and a model to calculate initial stiffness are accurately presented.