Experimental study on hysteretic behavior of aluminum alloy gusset joints

This paper presents the hysteretic behavior of aluminum alloy gusset (AAG) joints by means of experimental study. Eight AAG joint specimens are tested under cyclic load. Initially, the test program is introduced, and the test phenomena and failure modes are demonstrated. Subsequently, the hysteresis curves, skeleton curves of the specimens are plotted and discussed. The experimental results reveal that there are two kinds of failure modes of AAG joints under cyclic load. The deformation process and mechanical behavior under cyclic load can be summarized into four stages and five phases, respectively. Finally, based on the hysteresis curves and skeleton curves, the deformation ability, energy dissipation capacity, bearing capacity and stiffness degradation of the AAG joint specimens are evaluated, and the following conclusions can be drawn: (1) due to the existence of the gap between the bolt hole and the bolt shank, AAG joint specimens experienced bolt slipping during the experiment, hence the hysteresis loops of the AAG joint specimens are not very plump; (2) judged by the load-displacement hysteresis curves, the AAG joint has good deformation ability but poor overall energy dissipation capacity, which can be further improved; (3) the moment-relative rotation hysteresis curves are plumper than the load-displacement hysteresis curves, indicating that the joint zone has better energy dissipation capacity than the whole specimen; (4) with the increase of the thickness of the gusset plate, the AAG joint performs better hysteretic behavior including bearing capacity, deformation ability and energy dissipation capacity; (5) all of the specimen performed stiffness degradation under cyclic loading.