Project contact is Sylvain Ménard at Université du Québec à Chicoutimi
Assemblies with glued-in rods allow architectural freedom. They are in fact invisible since they are found in the mass of the structural element. Some work has begun to document this type of assembly by considering static tests in single-sided traction and single-sided creep tests (Verdet, 2016). In order to continue this effort to specify the limits of this type of assembly, it is proposed to consider the lateral forces for assemblies with single and multiple rod connections. This project will therefore aim to document the ability of these assemblies to carry lateral loads.
Project contact is Jean Proulx at Université de Sherbrooke
While glued-in rods meet a need for refined architectural design, do they respond to a seismic architectural design? Can they prevent destructive damage and ensure recovery efforts given that this system has singular anchor points? Do the braces and diaphragms have the same behavior as in traditional connector systems? Based on the work of Verdet (2016), modeling can identify the a priori behavior followed by a validation test on seismic table.
Long threaded rods have recently been widely used as a reinforcement of glued laminated timber in perpendicular to the grain direction. The recent research has thus focused mainly on the withdrawal properties of the threaded rods in the axial direction. Utilizing their large withdrawal stiffness and strength, the threaded rods can also effectively be used as connectors in moment resisting timber joints. Yet, in joints, the threaded rods are often imposed to a non-axial loading, due to inclination of the rod axis to the grain as well as loading direction different from the rod axis. No design models are currently available for the combined axial and lateral loading of the threaded rods. In the present work, the effects of the rod-to-grain and load-to-rod angles on capacity and stiffness of the threaded rods are investigated by use of experiments and finite element models. Based on those, analytical expressions for determining stiffness and capacity of axially and laterally loaded threaded rods are proposed, intended as a basis for practical joint design. Furthermore, effect of various boundary conditions applied at the rod-ends is studied.
In order to study the lateral resistance of reinforced glued-laminated timber post and beam structures, nine cyclic tests on full-scale one-storey, one-bay timber post and beam construction specimens were carried out. Two reinforcement methods (wrapping fiber reinforced polymer (FRP) and implanting self-tapping screws) and two structural systems (simple frame and knee-braced frame) were considered in the experimental tests. Based on the experimental phenomena and test results, feasibility of the reinforcement was discussed, contribution between different methods was evaluated, and the seismic performances of the specimens were studied. Results showed that both the two reinforcement methods could restrain the development of crack, and recover the strength, stiffness and energy dissipation capacity. It also showed that the lateral resistance could be improved significantly when the failed simple frame retrofitted by reinforcing the joint and adding knee-brace, and this approach can be very practical in engineering.
Project contact is Jean Proulx at Université Laval
The main objective of the research project is to assess the behavior of bonded rod assemblies under dynamic stresses. These wood / wood connections are used in solid wood frames and allow, among other things, to transfer the moment in beam-column connections. Their ability to dissipate energy under seismic loading will be evaluated by cyclic laboratory tests by varying the sections and configurations of the assemblies. The whole structure must be able to dissipate energy under dynamic loadings (earthquakes, wind) and the demand for ductility in the assemblies is considerable in rigid frame structures. This project will make it possible to characterize the behavior of timber / timber assemblies in glued rods under cyclic loads. The results obtained can be used by the partner for the seismic design of solid wood structures using these connections. Optimization and a better understanding of the dynamic behavior of these assemblies will also increase the safety of solid wood structures, and promote their acceptance in this developing market.
Glued-in rods (GiR) are an effective way to connect timber elements from both load bearing capacity/stiffness and aesthetic point of view. This method is also widely accepted as a method for reinforcement of the new and existing timber structures. Although GiR are widely used in timber structures, there is still no unified European test standards, product standards or design equations for such connections. At present, there are several test methods and procedures applied in research and development. In this paper two different methods for obtaining pull-out strength are presented. Furthermore, experimental investigation was conducted and results obtained from both methods are mutually compared. Pull – compression test procedure is the most common setup for experimental investigation, however this setup is sometimes not representative and it is often characterized as unreliable because it does not quite good correspond to practical applications. The second examined test procedure was pull-pull. Within the experimental investigation, total number of 36 specimens were tested and results obtained from both methods are shown, discussed and compared in this paper.
Glued laminated timber Tudor arches have been in wide use in the United States since the 1930s, but detailed knowledge related to seismic design in modern U.S. building codes is lacking. FEMA P-695 (P-695) is a methodology to determine seismic performance factors for a seismic force resisting system. A limited P-695 study for...