Mechanical performance of glulam beam-column moment-resisting connections with self-tapping screws as fasteners

Abstract

The innovation and improvement of connection technology is an important topic in the field of timber structure. With the development of manufacture process, the self-tapping screws or threaded rods with sufficient lengths and optimized threads provide an alternative way to realize the strong and stiff timber connection. The self-tapping screw applied as a fastener can cut threads by itself on the internal surface of a pre-drilled hole in wood, and thus establish the mechanical interlocking through the tight fit between the self-tapping screw and the wood. In order to expand the application of self-tapping screws in timber construction and explore diverse techniques to achieve timber connections with a capacity to resist moment, this paper presents experimental investigations on the glulam beam-column moment-resisting connections using self-tapping screws as fasteners. A series of withdrawal tests are carried out on 240 specimens to research the withdrawal property of self-tapping screws in glulam. A total of 16 full-scale beam-column connections with 8 different geometric configurations are tested under cyclic loading to research the mechanical performance of the connections regarding moment resistance, rotation stiffness, deformability, hysteresis characteristics, stiffness degradation and energy dissipation capacity. The results indicate that this type of connection with self-tapping screws is characterized by a high moment resistance and rotation stiffness, but not very considerable deformability and energy dissipation capacity.