Mechanical behaviors of the Assembled Hub (AH) joints subjected to bending moment

Abstract

To satisfy the demand for assembled construction of single-layer reticulated domes, a novel Assembled Hub (AH) joint with good mechanical performance and economic benefit is introduced in this paper. Two available connection types are developed to satisfy different engineering requirements. The theoretical solutions of the elastic stiffness and the bearing capacity of the new joint system are proposed based on the component method. A series of bending tests were conducted to investigate the failure mechanism of AH joints, and the FE analysis was carried out to simulate and verify the mechanical behaviors of AH joints. Finally, the strengthening effects of two kinds of stiffeners are carefully compared and discussed. The results indicate that the AH joints type I show excellent ductility in the loading process. The failure of joints is caused by the plastic instability of the hub or the excessive plastic deformation of the closure plate. The plastic moment resistance of joint is determined by the thickness, height, outer diameter and material of the hub, as well as the bolts pitch. By contract, the AH joints type II display lower ductility but higher bearing capacities in the loading process. The failure mode is the connection failure. The ring stiffeners have a better strengthening effect than the radial stiffeners. A comparison between the computations and the experiments highlights the validity of the suggested bearing capacity formulas, which can be further used to guide the joint design.