Experimental and numerical analyses on mechanical properties of aluminum alloy L-shaped joints under cyclic load

Abstract

The mechanical properties of the proposed aluminum alloy L-shaped (AAL) joints are studied in this paper. Seven different AAL joint specimens were tested under the cyclic load applied by an electronic servo-actuator. The experimental phenomena, modes of failure, ultimate displacements and ultimate loads were recorded. The hysteresis curves, skeleton curves, stiffness degradation curves and energy dissipation curves of the specimens are plotted and discussed. The three-dimensional (3D) finite element model of the AAL joints is established and the model is validated by the displacement-load curves. The parametric analyses considering thickness of the joints, friction coefficient and ribs on the joints are conducted with the validated finite element model. The experimental results indicate that there were two failure modes of the AAL joints under the cyclic load, and the bolts slipping phenomenon was apparently observed during the process, which causes the pinch phenomena in the hysteresis curves. Based on the experimental curves, the deformation process of the joints under the cyclic load can be concluded into three phases. The two highest bearing capacities of the specimens are 31.54 kN and 36.33 kN, which are 51.56% and 74.58% higher than those of the control specimen (BASE), respectively. The results of the parametric analysis reveal that the ribs and thickness of the joints are the most effective factors influencing the bearing capacity of the joints.