Study on the rotational performance of steel hub joints of wood reticulated domes subjected to monotonic and cyclic bending moment

Abstract

Steel hub joints with bolted steel side plates (SHJ-BSSP) has been widely adopted in wood reticulated domes, yet few studies have been conducted on its mechanical behaviour. This paper presents a refined finite model for SHJ-BSSP joints, which is verified against existing test results and used for further parametric study on the rotational performance of SHJ-BSSP joints subjected to monotonic and cyclic bending moment. The flexural stiffness and capacity of joints about the strong and weak axes is investigated, accounting for influences from axial compression and the number of shear bolts. The results indicate that the joints, under monotonic loading, demonstrate typical elastic-plastic behavior. Higher compression force and more shear bolts can enhance rotational stiffness and ultimate moment of the joint, while decreasing the ductility due to the earlier yielding of wood within the bearing region of the joint. Under cyclic loading, the hysteretic curves of joints exhibit an obvious pinched hysteretic behavior due to the clearances within the joint. As a result of the second order bending moment stemming from axial compression force, the slipping region of the hysteretic curves tend to deviate from the horizontal coordinate axis. Furthermore, larger compression and more shear bolts can increase the total energy dissipation of the system while decreasing the proportion of energy dissipation from the bolted connections. Conclusions are drawn regarding the feature and failure mechanism of the SHJ-BSSP joints, which are helpful guidelines for practical design.