MECHANICAL PROPERTIES OF A NOVEL JOINT OF A SINGLE-LAYER ALUMINUM-ALLOY COMBINED LATTICE-SHELL STRUCTURE

To overcome the shortcomings of traditional aluminum-alloy gusset joints. i.e.. the low bearing capacity caused by the lack of a shear connector that makes these joints unsuitable for an aluminum-alloy combined lattice-shell structure of a larger span, this paper proposes a novel joint with a high bearing capacity that has a cylindrical socket-and-spigot type shear connector at the center of the joint. Experimental research was carried out on the novel joint. The results show that the overall stiffness and shear resistance of the novel joint are greatly improved compared with those of a traditional gusset joint and that the out-of-plane bending capacity is more than 50 % higher. The failure mode of the novel joint is mainly manifested by tension and shear block failure of the lower cover plate when the thickness of the gusset plate is small and torsional buckling failure of the connected aluminum-alloy beam. An elastoplastic finite-element parametric analysis based on multiple contacts shows that the bearing capacity of the proposed joint is related to the thickness of the connecting plates and the diameter and number of bolts. Based on the working mechanism of the novel joints, this paper offers a simplified calculation formula for the ultimate bearing capacity of the joint. The results of this paper can provide a theoretical basis for making and revising the design codes for this novel joint.