The majority of low-rise residential structures in the U.S. are constructed with wood. Wood-based composites are primary building materials in these structures, used as structural sheathing, joists, and beam components. Wood composites are susceptible to degradation upon exposure to high levels of moisture. Moisture durability is routinely assessed with accelerated...
Western juniper (Juniperus occidentalis) is a conifer that is native to Oregon, California, Washington, Nevada, and Idaho. Juniper is known to have highly decay resistant heartwood and is a popular choice for finished furniture. With recent forest management practices over the past 100 years have resulted in an immense population...
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ArijitSinha
Western juniper (Juniperus occidentalis) is a conifer that is native to
Western juniper (Juniperus occidentalis) is a “native invasive” tree species in Eastern Oregon. It is extremely good at finding and consuming water in arid climates, which makes it difficult for other plant species, especially sagebrush and grasses to survive. Sagebrush and grasses are necessary for the survival of the sage...
Mass timber (MT) offers viable eco-conscious solutions within the building industry, with its high strength ratings, dimensional stability, light weight and renewable nature enhancing its status as a low carbon alternative to conventional building materials like steel and concrete. Moisture intrusion, coupled with the inherent organic nature of wood pose...
The engineering community is increasingly moving towards the design of seismic force-resisting systems that limit post-earthquake damage and reduce downtime to increase urban resiliency. For example, structural spines can be used to provide an elastic load path to impose a more uniform drift distribution with building height, thereby reducing the...
To quantify the postpeak residual capacity and
to gain insights into the load transfer mechanism of a shear
wall, nail connection tests were performed on salvaged
connections after a monotonic shear wall test loaded up
to peak load. Experimental results reveal that there is a
loss of strength in most...
Engineers, in practice, are often faced with the challenge of evaluating a fire-damaged structure and developing a rehabilitation and retrofit plan. In order to decide on a rehabilitation and retrofit plan, information on thermal degradation of building materials and connections are vital. A critical knowledge gap exists in terms of...
The overall goal of this study was to gain an insight into the load sharing aspect between oriented strand board (OSB) and gypsum wall board (GWB) in shear wall assembly during racking load. More specifically the objectives of the study were to: (1) evaluate qualitatively the load sharing between OSB...
The advent of synthetic adhesives has transformed the structural applications of wood. However, a persistent issue in adhesively-bonded wood products has been moisture durability. When designing wood based composites, moisture durability will depend on both the wood phase and the adhesive phase. A key question, therefore, is how does one...
With growing interest in mass timber, especially mass timber panels (MTP), there has been a need to better understand their structural properties. One of the most versatile uses for MTP are as floor systems. Under new code provisions, these floors can be utilized in new and taller building types, but...
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Christopher Higgins ArijitSinha
With growing interest in mass timber, especially
Cross-Laminated Timber (CLT) is a prefabricated building material that is relatively new to the United States and North America. It consists of no less than three layers of graded, dimensional lumber glued in alternating longitudinal and transverse layers to create a panel that can be used for various building applications...
Concrete formwork is a common type of temporary structure used on construction projects. Due to difficulties in considering actual construction site implications during formwork design, assessments of formwork integrity are often made in the field by site personnel based on subjective visual inspection. The use and re-use of concrete formwork...
The effect of grain angle (GA) on shear strength of Douglas-fir has been evaluated. Shear block specimens with a GA varying from 0 to 90° was loaded in the shear plane, resulting in failure mode transitioning from parallel to grain shear to rolling shear. As expected, shear strength decreased as...
The effect of grain angle (GA) on shear strength of Douglas-fir has been evaluated. Shear block specimens with a GA varying from 0 to 90° was loaded in the shear plane, resulting in failure mode transitioning from parallel to grain shear to rolling shear. As expected, shear strength decreased as...
Timber-concrete composite (TCC) floors have improved strength and stiffness when compared to timber-only floors, allowing for longer spans in buildings and improved life safety. However, North America does not have codes and standards that recognize TCC floors, particularly the improved life safety performance of these floors in fire. Therefore, alternate...
Timber-concrete composite (TCC) solutions originated in the early twentieth century. There has been a renewed interest in TCC solutions in modern mass timber buildings, especially for floor systems. However due to lack of data, design standards, and code acceptance, TCC solutions require that new mass timber solutions be tested, and...
The development of cross-laminated timber (CLT) panel technology has opened up new opportunities for wood in tall buildings. Several characteristics including seismic performance and speed of construction have raised interest among designers. As CLT gains acceptance in the industry, alternative structural solutions need to be investigated to improve performance of...
Connections in mass timber structural systems dissipate energy and transfer lateral forces from mass timber elements such as shear walls and diaphragms, providing critical load paths. Cross-laminated timber (CLT) is a prominent mass timber material used to manufacture wall and floor assemblies. Fire performance research of CLT walls and floors...
Cross-laminated timber (CLT) is revolutionizing the use of wood in the construction sector of North America as a solution for walls and diaphragms in mid-rise or even high-rise timber structures on account of its environmental advantages, high strength-to-weight ratio, fire-safety performance, and propensity for prefabrication. However, considering the hygroscopic nature...
Engineered wood composites are used in many structural applications and are intended for dry use. However, these materials may encounter significant amounts of wetting while in service, which can lead to structural failures. This study combined aspects of wood science, mechanics, structural engineering, and mycology to assess changes in material...
Cross-laminated timber (CLT) panels have been gaining popularity as diaphragm elements in mid- to high-rise construction projects. In addition, CLT-concrete composite (CCC) diaphragms have been implemented to expand the use of CLT diaphragms. To understand the behavior of CLT and CCC diaphragms, this research effort sought to characterize the cyclic,...
Sandwich composites are typically produced from two high strength facings bonded to a lower strength, lightweight core. Sandwich design has proven to be efficient for applications demanding high strength and low weight. Wood-based sandwich composites have been largely limited to non-structural applications with the exception of structural insulated panels and...
As oriented strand board (OSB) increases in use as an engineered wood product, improving the in-plane shear properties will allow more efficient use of the material as well as open up other opportunities for OSB to be used in engineered wood products with high shear stresses. Based on classical laminated...
One of the recent additions to the panoply of engineered wood products is cross-laminated timber (CLT). CLT is a prefabricated, large-scale, solid wood panel that consists of multiple layers of lumbers stacked together, with each layer arranged perpendicular to the next layer, glued with structural grade adhesives, and pressed. The...
Organizations are significantly influenced by corporate cultures of the interacting organizations. Both the construction industry and engineered wood products (EWP) manufacturing industry are generally known for operating in a traditional environment maintaining conservative corporate cultures, which can create friction when they try to interact with a more liberal architectural industry...
There are over 130 million wood poles supporting electrical transmission and distribution lines in the U.S. The vast majority of these poles are preservative treated to prolong their useful life. In some cases, however, the depth of treatment is relatively shallow, leaving a deep zone of moderately durable, untreated heartwood....
Civil engineers are aware of the impacts of structures on the global environment but the environmental impacts of a fire within these structures remains unknown. Fires present a unique hazard as it is difficult to predict the probability of the occurrence and the intensity. Traditional methods to identify the environmental...
Moisture durability is essential for wood composites, especially those used in building construction, where products are prone to weathering. The primary focus of this research was to determine if adhesive penetration into the cell wall has a positive influence on adhesive bond durability. To fully understand the measureable effects of...
In the residential sector, wood is the predominant construction material. In the commercial sector and in mid‐rise construction, the use of wood is limited because of a multitude of reasons, including building code restrictions, the perception of wood as a structural material, fire code requirements, and lack of knowledge and...
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ArijitSinha Thomas H. Miller
In the residential sector, wood is the
Conflicts and disasters displace millions of populations worldwide. There is a need for rapid and affordable housing to cater to the needs of the displaced and unhoused population. Experience from previous post-disaster responses shows that temporary housing should be rapidly deployable, planned for months to years, and should be environmentally...
Since 2004 there have been multiple devastating tsunamis around the globe triggered by large magnitude earthquakes; with the most recent being the Tohoku, Japan tsunami in March 2011. These tsunamis have caused significant loss of life and damage to the coastal communities impacted by these powerful waves. The resulting devastation...
This study investigated the effect of exposure to elevated temperature on the yield strength of single-shear nail connections when subjected to lateral loading. Solid sawn lumber and laminated veneer lumber were used as framing members and two different thicknesses of both oriented strand board and plywood were used as the...
Wood and wood-based composites are being used extensively in single-family residential dwellings. Therefore, it is important to categorize their response when exposed to elevated temperatures for a sustained period of time. In fire-resistant design for wood structures, the main goal is to ensure that enough structural integrity is maintained, during...
Wood and wood-based composites are being used extensively in single-family residential dwellings. Therefore, it is important to categorize their response when exposed to elevated temperatures for a sustained period of time. In fire-resistant design for wood structures, the main goal is to ensure that enough structural integrity is maintained, during...
For wood beams, it is often assumed that the neutral axis (NA) is located at the centroid of the beam. This would be the case for isotropic and homogeneous materials but these prerequisites are not valid for wood. The varying grain patterns and knots located throughout wood make wood anisotropic...
For wood beams, it is often assumed that the neutral axis (NA) is located at the centroid of the beam. This would be the case for isotropic and homogeneous materials but these prerequisites are not valid for wood. The varying grain patterns and knots located throughout wood make wood anisotropic...
Global sustainability goals have led to the development of the green building movement. The Green Building Program, stemming from the movement, has had unprecedented success as it provides a quantifiable metric to people’s efforts towards sustainable development. Sustainable development and green buildings are often used interchangeably. Although, sustainable development and...
Global sustainability goals have led to the development of the green building movement. The Green
Building Program, stemming from the movement, has had unprecedented success as it provides a quantifi able
metric to people’s efforts towards sustainable development. Sustainable development and green buildings are often
used interchangeably. Although, sustainable development...
Fracture toughness of wood and wood composites has traditionally been characterized by a stress intensity factor, an initiation strain energy release rate (G init) or a total energy to fracture (G f). These parameters provide incomplete fracture characterization for these materials because the toughness changes as the crack propagates. Thus,...
Fracture toughness of wood and wood composites has traditionally been characterized by a stress intensity factor, an initiation strain energy release rate (G[subscript init]) or a total energy to fracture (G[subscript f]). These parameters provide incomplete fracture characterization for these materials because the toughness changes as the crack propagates. Thus...
The construction industry has relied heavily on wood and wood-based composites, such as oriented strand board (OSB) and plywood for timber frame construction. Therefore, it is highly imperative to categorize the response of wood-based composites when exposed to elevated temperatures for a sustained period of time. The essence of fire-resistant...
With growing awareness of the negative impacts of the built environment, solutions for dramatic environmental, economic, and social improvements are sparking in all sectors, especially within the construction industry. The work of this thesis aims to quantify and compare social, economic, and environmental impacts of a three-story mass timber structure...
Timber engineering is currently in the midst of a significant evolution due to the rise of mass timber products, like cross-laminated timber (CLT). Increasing numbers of structural engineers are facing the challenge of designing lateral-force-resisting systems (LFRS) for multistory CLT structures. LFRS solutions such as steel frames, concrete cores, or...
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ArijitSinha Thomas H. Miller
Timber engineering is currently in the midst of a
Wood shear walls are the main lateral force-resisting system for wood-frame construction. Water intrusion and subsequent decay around connections can significantly impact shear wall behavior, but these problems are seldom studied. In this study, effects of water intrusion and fungal attack on shear wall capacity were examined using small-scale (610-...
Wood I-joists are often left uncovered and exposed to the weather during construction, allowing the oriented strandboard and laminated veneer lumber in these systems to be adversely affected by water absorption. Manufacturers typically specify that these materials be protected from wetting, but this can be difficult in wetter climates. There...
Routine inspection of wood utility poles to detect internal decay involves drilling holes at or about the ground line. While these holes are useful for detecting internal decay, their presence raises concern among engineers about their potential effects on pole flexural properties. The effect of inspection holes on flexural properties...
Residential energy use is a significant contributor to greenhouse gas emissions and climate change. Reducing energy efficiency in conventional wood-framed houses are thermal bridges: direct paths that allow heat to flow through the studs instead of the insulation. One suggestion for reducing thermal bridging is the staggered stud (SS) wall....
Compression perpendicular to grain (C┴) of wood is an important property and has a drastic effect on serviceability of the structure. Typical C┴ loading scenarios include the bottom chord of a truss resting on the top plate of a shear wall and chords of a shear wall resting on the...
Current compression perpendicular-to-grain (C⊥) design values for wood members are based on mean stress obtained from ASTM D143 specimen. The standard ASTM test with metal on wood bearing has limited applicability in modern construction assemblies with C⊥ loading scenarios. Previous work has shown that end-bearing conditions and wood-on-wood C⊥ bearing...
Current compression perpendicular-to-grain (C-perpendicular to) design values for wood members are based on mean stress obtained from ASTM D143 specimen. The standard ASTM test with metal on wood bearing has limited applicability in modern construction assemblies with C-perpendicular to loading scenarios. Previous work has shown that end-bearing conditions and wood-on-wood...
This thesis focuses on the fundamental behavior of CLT floor-to-wall connections during a fire.
Cross-laminated timber (CLT) panelized structures rely on floor-to-wall connections for the load path and stability of the structure. Additionally, the fire performance of these connections is critical to prevent horizontal or vertical fire spread within these...
Wood-based composites (WBCs) are an important sector of the US economy. For a WBC product to succeed, understanding its long-term durability, including seasonal variations in temperature and humidity, is critical. Durability is especially important WBCs because they are predominantly made from wood, which is a biological, hygroscopic material that is...
With mechanization, the logging industry has experienced a decreasing trend in the total number of workplace accidents, especially as new technology is making harvesting safer. However, there are areas within harvest units such as extremely steep slopes or rocky outcrops that are inaccessible to machines and are required to be...
As non-renewable resources dwindle and costs increase, it becomes ever more important for people to understand and control their electricity usage. Eco-feedback devices are being developed to increase user awareness and reduce consumption. In order for feedback devices to be successfully adopted into the home, however, they must be appealing...
Free/Open Source Software (FOSS) communities often use open bug reporting to allow users to participate by reporting bugs. This practice can lead to more duplicate reports, as inexperienced users can be less rigorous about researching existing bug reports. The purpose of this research is to determine the extent of this...
Recent climate projections predict more frequent and severe drought conditions in western Oregon which is a threat to forest health, productivity, and structure. Land managers are increasingly concerned with how to create forest drought resistance: a tree or stand’s ability to maintain its growth rates during a drought, and resilience:...
High Performance Concrete (HPC) is used in our crucial pieces of infrastructure, such as bridge decks, due to its enhanced durability and engineering properties. However, HPC is highly susceptible to early-age cracking. Cracking within the first months of a bridge deck’s lifespan can severely hinder its long-term performance and durability....
Many nondestructive techniques for structural health monitoring are subjective and based on visual observations of degradation. In addition, dynamic properties of structures are already used to obtain quantitative structural health data. However, most current data collection is limited to localized damage on the structure, rather than global response. Recent research...
Architects and engineers are two key types of design professionals who influence the use of wood products in construction. Eighty to ninety percent by volume of all residential structures in the U.S. are wood (Gupta, 2005). In 2010, the non-residential market was made up by 10% wood, 60% steel and...
Wood plays a key role in modern electrical infrastructure; crossarms and power poles utilize the high strength to weight ratio, availability and low cost of wood to facilitate the access of power to millions of Americans. However, wood presents a variety of challenges as a material. In structural applications, one...
The objective of this research is to support DfX considerations in the early phases of design, particularly Design for the Environment. In order to include DfX considerations, especially early in the design process, there needs to be access to knowledge and information that is usually only applicable further downstream in...
The goal of this project is to contribute to the development of design values for cross-laminated timber (CLT) diaphragms in the seismic load-resisting system for buildings. Monotonic and cyclic tests to determine strength and stiffness characteristics of 2.44 m (8 ft) long shear connections with common self-tapping screws were performed....
In bioacoustics, automatic animal voice detection and recognition from audio recordings is an emerging topic for animal preservation. Our research focuses on bird bioacoustics, where the goal is to segment bird syllables from the recording and predict the bird species for the syllables. Traditional methods for this task addresses the...
Spintronics is an emerging field of research dealing with devices that can potentially exploit the additional degree of freedom provided by the electron spin along with or instead of the conventional electronic charge. One of the most promising aspects of spintronics is the potential use of magnetostatic spin waves as...
The Focused Ion Beam (FIB) tool is a versatile instrument for nano-machining in
circuit editing. Circuit editing is one of the most important steps in the design of an
electronic circuit on a chip. Circuit editing can be improved by imaging of silicon
plates and analyzing the resultant images. However...
Oregon State University has conducted research in collaboration with TerraPower, LLC,
to perform a top-down scaling analysis of an integrated test facility. The goal of this
facility is to simulate transient and quasi-steady phenomena at a reduced scale,
including steady-state operation, pump coastdown, natural circulation, reactor head heat
transfer, and...
The objective of this project was to evaluate methods to remediate a wood I-joist with a single, circular hole in the web while leaving utilities in place. The methods were experimentally evaluated with a full-scale bending test using four equally spaced point loads. There were three depths of joists with...
The purpose of this thesis was to evaluate orthogonal cutting as a method to determine the fracture toughness of low and high density polyethylene and wood plastic composites. A test fixture was developed to capture normal and tangential cutting forces at variable depth and rake angle. A tool interface method...
The behavior of mass timber beam-to-column connections under seismic loading is not yet well understood. Mass timber beam-to-column connections must have the ability to maintain load-carrying capacity despite the deformations that will be imposed on all components of the building during seismic events. This behavior is called deformation compatibility. The...
The United States generates over 70 million tonnes of wood waste annually, with over 27 million tonnes still available for recovery. Current recycling rates for wood waste are in the range of 10% to 15%, which is much lower than other common building materials and indicative of an underutilized resource....
Spintronics is an emerging field of research wherein the electron spin instead of, or along with, the conventional electron charge may be utilized in developing next generation logic devices. One of the most promising aspects of spintronics is that information transfer may be achieved by spin waves in logic devices,...
Many wood composites are known to poorly resist the effects of moisture and temperature extremes over time. Degradation of adhesive bonds, irreversible thickness swell and dimensional instability result in a decrease of properties and a possible failure of the material. Accelerated weathering has become an essential tool for assessment of...
Mass timber is emerging as a viable form of construction around the world in new markets for wood buildings. The entrance into these markets has driven the demand for more knowledge to enable designs alongside other structural materials such as steel and reinforced concrete.
Large, in-plane tests on cross-laminated timber...
A Life Cycle Assessment (LCA) of the production of poplar biomass grown under four management conditions in the Pacific Northwest (PNW) of the U.S.A. was conducted. While the extraction of fossil fuels and the subsequent generation of energy have environmental impacts, the alternative of extracting poplar biomass also has impacts...
The objective of this study was to develop and validate practical modeling
methods for investigating load paths and system behavior in a realistic, light-frame wood
structure. The modeling methods were validated against full-scale tests on subassemblies
and an L-shaped house. The model of the L-shaped house was then modified
and...
There are about 80 million single-family dwellings (SFD) in the United States, predominantly of wood-frame construction. Of these, 68% are owner occupied. A home is typically the largest single investment of a family, and is often not covered by earthquake insurance, even where it is available. Of all SFD in...
The Comprehensive Nuclear-Test-Ban Treaty (CTBT) prohibits the testing of nuclear weapons on the face of the earth. The detection of atmospheric radioxenon (131mXe, 133m/133Xe, and 135Xe) plays an important role in the identification of sub-surface clandestine nuclear weapon explosions. Since the radioxenon identified above decay via two radiation in coincidence,...
Cross-laminated timber (CLT) is a massive engineered wood product made of orthogonally bonded layers of solid-sawn lumber, and is intended for roof, floor, or wall applications. Although it was developed in Europe in the early 90s, CLT is relatively new to North America.
CLT products must be certified for structural...
Policy regarding the management of public forests has undergone a drastic shift over the past couple of decades due to the loss old-growth forests in the Pacific Northwest (PNW) of the United States. For much of the 20th century, forest management on public lands emphasized timber production through the use...
Several standardized courses for Formula SAE (FSAE) testing are introduced and described with sufficient detail to be reproduced by any Formula SAE team. Basic analysis methods for the courses are given as well as explanations of how those analyses could be used. On-car data from the Global Formula Racing (GFR)...
Focus is published by Oregon State University College of Forestry. Our goal is to keep Forestry alumni, friends, faculty, staff, and students informed about the College of Forestry and its many activities and programs.
It is commonly accepted in the analysis of wood beams that the neutral axis coincides with the beam's centroid. However, wood is not an isotropic material, has different elastic properties in the tangential, radial and longitudinal directions, and is non-homogeneous, as it contains characteristics such as knots. Therefore, there is...
Focus is published by Oregon State University College of Forestry. Our goal is to keep Forestry alumni, friends, faculty, staff, and students informed about the College of Forestry and its many activities and programs.
The forest products industry relies on the production of high-quality wood to satisfy consumer requirements. Improving wood quality requires an effective and inexpensive technique for measuring critical properties such as density and microfibril angle. An emerging technology known as near-infrared hyperspectral imaging (NIR HSI) essentially captures surface images of samples...
Concrete has been categorized as a key contributor of CO2 (carbon) emissions into the atmosphere. This is mostly associated with the production of ordinary portland cement (OPC). The concrete and cement industries are pursuing a path to reduce their carbon emissions generally in accordance with the climate change goals outlined...
The increased demand for building materials that are friendly to the environment, along with the latest advances in wood science and technology, which exploit the fiber orientation of wood, resulted in composite wood materials known as mass-timber products. To understand the effects the wood fiber orientation has on the dynamic...
Polyethylene terephthalate (PET) polymer has been the material of choice for packaging industry as a result of its excellent mechanical and physical properties. These properties are highly dependent on the microstructure, chemistry, and processing conditions of this material. PET is often oriented in the machine direction (MD), the transverse direction...
In many composites, fiber bridging develops as part of the fracture process. Fiber bridging invalidates many toughness evaluation methods such as the ASTM E399 and complicates the identification of crack length, which is a necessary parameter in energy methods. In order to measure the toughness of fiber bridging composites, an...
Each year the United States: Forest Service (USFS) spends billions of dollars fighting forest fires. One strategy used by the USFS to prevent catastrophic fires is through forest restoration programs, in which potential forest fuel is removed through mechanized thinning. This program is expensive and generates high volumes of small-diameter...
Focus on Forestry is published by Oregon State University College of Forestry. Our goal is to keep Forestry alumni, friends, faculty, staff, and students informed about the College of Forestry and its many activities and programs.
Generally presented as a preferred social norm based on both ethical considerations and legislative demands, gender equality has been highly encouraged in recent years. For instance, The United Nations Sustainable Development Goals for 2030 call out achieving gender equality and empowerment of women. However, although there are multiple efforts to...
The objective of this study was to compare light wood framing and traditional timber
framing quantitatively through environmental impact assessment and load path analysis. This
research was inspired by a traditional timber frame structure constructed in Vermont in 2011, and
the design of structures considered within reflect the general characteristics...
Cross-Laminated Timber (CLT) is one of the latest engineered wood products to show promising structural features for a variety of structural purposes including resisting lateral loads. For CLT to be widely adopted, its modal behavior needs to be fully evaluated through experimental and numerical methods. It is important to the...
Wood composites are an important renewable structural material which can be a net carbon sink when used in combination with sustainable forest management practices and high rates of log utilization. Adhesive bondlines are an essential part of composites, and for wood composites, they determine the moisture durability and mechanical performance...
Successful ecosystem restoration requires an understanding of the ecological processes directing succession. One of the challenges in the semi-arid grasslands of western United States is replacement of native species by invasive annual grasses. Solutions to this problem require identifying and manipulating ecological processes that direct succession to favor desired vegetation....
Distributed version control allows developers to manage software evolution among distributed development teams. But it does not eliminate all consistency and concurrency issues, and instead introduces additional complexity when merging code. And resolving merge conflicts is nontrivial when automated merging fails. In such cases, developers are forced to inspect the...