Bolted joints for small and medium reticulated timber domes: experimental study, numerical simulation, and design strength estimation

This paper proposes a new type of bolted glulam joint for small-span and medium-span reticulated timber dome structures. The joint fastens the timber elements and the angled slotted-in steel plates together with steel bolts. Reasonably simplified experiments were designed and conducted to understand the mechanical properties of the proposed joint. Finite element models were also developed and calibrated with the tested results. A four-line model was provided to explain the mechanical properties of the joints, which were observed from the tests and simulations. To facilitate the future use of the proposed joint, theoretical derivations were provided to estimate its mechanical features. According to the estimation equations, bilinear moment–rotation curves could be easily obtained for the joints with different wood species, member sizes, joint designs, and/or bolt diameters. Finally, full-size structural models were created to investigate the static stability of K6 single-layered reticulated timber domes with the proposed joints. The influences on the ultimate structural stability capacity from the span, the rise-to-span ratio, the joint model (i.e., stiffness), the initial geometric imperfection introduced from the construction, and the load distribution were systematically investigated.