Feasibility of improved slotted bolted connection for timber moment frames

Abstract

This note examines the feasibility of an improved slotted bolted connection for timber moment frames. In the present connection, steel tubes are inserted into drill holes in glulam, and the steel tubes are fixed to the glulam with resin injection. Aluminum splice plates with curved slots, or curved elongated holes, are fastened mechanically by using high strength bolts that go through the steel tubes. Since the compression due to bolt tension is fully supported by the steel tubes, reduction of bolt tension due to shrinkage of glulam can be avoided. The use of slotted aluminum splice plates allows stable energy dissipation due to smooth sliding between the aluminum splice plates and the end surfaces of the steel tubes within the specified range of rotation angle. Through quasistatic cyclic loading tests of two connection specimens, it was demonstrated that stable and nearly rigid-plastic hysteresis loops were obtained whose equivalent viscous damping ratio was more than 30 % in the ranges of rotation angle close to or over 1/50 radian. Although further improvement is necessary, the experimental results demonstrate the feasibility and potential of the present connection.

Reinforced moment‐resisting glulam bolted connection with coupled long steel rod with screwheads for modern timber frame structures

“…[ 18,19 ] The second approach is to use various kinds of components to strengthen the connection at the structural level, which aims at increasing the rotational stiffness of the connection. Some of the existing solutions have applied the hollow variable‐wall‐thickness bolts, [ 20 ] the hollow steel dowels with injected epoxy resin, [ 21 ] steel dowels with expanded tube fasteners, [ 22 ] the plain round rods, [ 12 ] the self‐drilling dowels, [ 14 ] the pre‐stressed tubes, [ 23 ] the knee braces, [ 24 ] the steel angles, [ 25 ] and the friction dampers [ 26 ] to the bolted connections.…”

Experimental static and seismic behaviour of glulam beam-to-column connection with screwed-in threaded rod joints

“…The dowel-type connection is widely used in timber structures for its good economic performance, convenient assembly, and reliable force transmission (Liu and Yang 2019). However, traditional dowel-type connections show significant limitations on the connection load-carrying capacity and stiffness (Lam et al 2010;Araki et al 2011;Wang et al 2015). As a result, it is usually considered as a hinge connection (Li et al 2021), which deeply restricts the development of multi-story and long-span structures.…”

Restoring Force Model of an Energy‐Dissipation Joint in Hybrid Frames: Simplified Skeleton Curve and Hysteretic Rules

“…e dowel and bolt are the most commonly used joints in modern wood or EBP buildings, whose ductility is achieved by means of the plastic deformation in metallic connectors [11][12][13][14][15]. Conversely, in heavy portal frames, the energy-dissipation capacity of the connections turns out to be relatively low because of the limited number of joints.…”