Mechanical performance of AH joints and influence on the stability behaviour of single-layer cylindrical shells

Abstract

Abstract Previous studies on the mechanical performance of AH (assembled hub) joints mainly focused on the axial capacity and the bending capacity of the joint system. However, the joint system in latticed shells is subjected to combined axial forces and bending moments in practice. In this paper, the mechanical performance of joints under eccentric load is investigated experimentally and numerically. The eccentric bearing capacity, as well as the failure mechanism of the novel joint system, are derived and compared with the axial loading and pure bending conditions. The correlation curve with 95% guaranteed rate is determined by non-linear regression analysis. On this basis, a combined non-linear spring model is established to simulate the mechanical performance of joints in single-layer cylindrical shells for stability analysis. The results indicate that for orthogonal type cylindrical latticed shells with diagonals or crossed cables, the stability reduction factor can reach a range of up to 0.8 to 0.96. However, for cylindrical latticed shells with lamella grids or three-way grids, the stability reduction factor is less than 0.62. This situation can be improved by strengthening the joint system or reducing the intersection angles of members. When the intersection angle decreases from 90° to 60°, the stability reduction factors of lamella shells will increase by 34%–47%. This means that cylindrical shells with AH joints have sufficient stability to meet engineering requirements by rational design.