Key parts of the lateral force resisting system in wood-frame buildings
are the shearwafls and the connections. The connections in wooden buildings
are the primary source of ductility and energy dissipation; these are essential
properties when buildings are exposed to lateral forces, such as wind and
earthquakes. Shearwall design is...
Nailed connections have nonlinear load-displacement
relations. Modeling these connections in an assembled
structure would require a great amount of computational time
because of the large number of degrees of freedom.
Replacing these connections with energetically-equivalent
nonlinear springs reduces the number of degrees of freedom,
and leads to computational efficiency in...
The reinforcement of wood and wood composite structural products to improve
their mechanical properties has been in practice for many years. Recently, the use of high-strength
fiber-reinforced plastic (FRP) as a reinforcement in such applications has been
commercialized.
The reinforcement is manufactured using a standard pultrusion process or
alternatively a...
Biaxial strength characteristics of wood-based structural panels were evaluated by
using analytical and experimental methods. Cruciform plywood specimens were tested
under biaxial tensile-tensile, compressive-compressive loadings in a symmetrically-jointed-
arm test fixture, which was mounted on a universal testing machine. Performance
of the test fixture was also evaluated during the tests....
In a majority of light-frame wood buildings, studs
and joists are the basic structural components in walls
and floors. The walls act as bending and compressive
panels and transmit lateral wind and gravity loads to the
foundation. Joists are used in floor systems, and
together with the sheathing member act...
The light-frame wood structure is an assemblage of
several components such as walls, floors and roof connected
by intercomponent connections such as nails or metal plates.
The behavior of the full-structure is determined by the
behavior of the individual components and connections.
Whereas individual substructures were investigated both
experimentally and...
With high costs of testing and rating a structural system for
fire resistance, the utilization of computer simulations that
approximate the integrity of structural subsystems could conceivably
reduce development costs. Before an analysis of a light-frame wood
system can occur, information on the components of the substructure
must be known....
Service life prediction models for light-framed wood structures require an extensive quantity of empirical data on deterioration pathologies for the numerous structural components, as well as mechanistic approaches to determine their capacity at various levels of deterioration. The data and models presented in this study satisfy a portion of the...
Light-frame construction practices and materials have changed greatly
over the past 100 years. Contemporary research has focused on modern construction; thus, we know a great deal about the behavior of modern lightframe buildings under lateral forces. However, there are many light-frame buildings that were built prior to the introduction of...
Heavy timber framing relies primarily on bracing to withstand lateral loads due to earthquakes and wind events. Bracing configurations in heavy timber framed buildings vary widely and include cross bracing, knee bracing, and other geometries. Many heavy timber frames constructed during colonial American times are still standing, exceeding the expected...
Friction dampers have been used successfully to dissipate seismic
energy in steel and concrete structures. The application is new to timber
structures. The objectives of this research were to design a slotted bolted
connection (SBC) and evaluate its potential as a passive energy damper in
timber brace.
The research was...
The goal of this study was to optimize a through-boring pattern that will provide adequate preservative penetration while minimizing the reduction in overall pole bending strength. Hole spacing was developed using longitudinal and transverse chemical penetration data from previous studies. Finite element analysis was used as a preliminary assessment tool...
It is difficult to treat the heartwood of many wood species with liquid preservatives using conventional liquid processes. Supercritical fluids (SCF) used as carriers of preservatives to impregnate refractory wood species may be an attractive alternative to conventional liquid carriers. While SCF impregnation has many potential advantages, some wood species...
Engineering analysis of heavy timber structures under dynamic loads
is generally lacking. Some literature suggests that heavy timber structures
are stiffer than expected, but popular engineering opinion is to the contrary.
In addition, prior research has shown that passive friction dampers can be
used in timber structures for the intended...
As a result of its atomic structure, carbon fiber produced from mesophase pitch
has a high electrical conductivity and high tensile strength. Others have used carbon fiber
as a resistive heating unit to accelerate matrix solidification in carbon fiber-polymer
matrix composites.
In this study, a unidirectional carbon fiber reinforced polymer...
Recently, fiber-reinforced plastics (FRP lamina) have
been applied to glued-laminated (glulam) timber for the
purpose of improving bending strength and stiffness.
Initially, full length reinforcement using FRP lamina was
developed. However, the cost of FRP lamina is a significant
portion of the total cost of reinforced glulam. Therefore,
it is...
In recent years, log structures have been marketed as an alternative
to conventional light-frame wood structures. Log structures are constructed
using round timbers (or manufactured timbers) that are stacked vertically
and have interlocking corners. Thru-rods and lag screws are used to
provide inter-log connections. This project was conducted to evaluate...
Tree nuts have been implicated in a number of foodborne outbreaks and recalls in recent years linked to enteric pathogens, particularly Salmonella. Therefore, prior to distribution and marketing, it is necessary to understand the biological risks associated with the consumption of tree nuts and to find effective methods to inactivate...
Rare plant reintroductions are a critical conservation tool for the augmentation of diminishing populations, or re-establishment of extirpated populations. Analysis of reintroduction failures suggests that a sophisticated understanding of species biology, ecology, and habitat is essential for producing self-sustaining rare plant populations. This study sought to generate that background knowledge...
