Digital image correlation (DIC) uses pairs of images, one in a reference state and one after in situ manipulation of the object, to measure full-field displacements and strains by tracking the motion of small image subsets. Subset selection is always a crucial part of DIC technique as it has a...
Thousands of children and adults suffer from fine motor skill deficits due to developmental disabilities or brain trauma. In order to acquire or reclaim these precision motor movements, occupational therapists work closely with each patient to develop the muscle memory required for completing tasks such as handwriting or drawing. Although...
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Brian K. Bay
Thousands of children and adults suffer from fine motor skill deficits due to
This dissertation details the application of digital image correlation (DIC) in novel methods for mechanical testing and shape characterization. The first usage manifested in the development of a novel composite test specimen that provided the ability to characterize the matrix compression energy release rate at initiation and subsequent crack propagation....
Metallic foams have become widely available and have unique properties
that make them attractive for use in a variety of engineering applications. Due to
their complex structure, the behavior of foams under complex loading conditions
is a subject of continued research.
Digital volume correlation is a technique wherein full-field strains...
An Achilles tendon injury can be devastating. Surgical methods to bring the muscle to full strength are not always available. Proposed is an ankle foot orthosis (AFO) that is entirely passive (does not add energy to the system) and uses the mechanical advantages provided by the walking gait of a...
Background: Hip replacements are considered routine operations which improve the quality of life in patients by reducing pain and restoring function. There are many variations in prostheses with varying benefits and disadvantages.
Methods: Literature from the United States and Europe was collected on total hip replacements between 2001 and the...
Local material damage that occurs within cellular solids, such as polymer foams and trabecular bone, and precedes local fractures of the cell struts or walls is called micro-damage. The accumulation of micro-damage within cellular solids is often undesirable, although it is thought to be vital to the development and health...
Interbody fusion cages are increasingly used in the treatment of spinal disease and injury in order to stabilize movement and promote arthrodesis of the vertebral bodies, but the micro-mechanics of the interaction between the cage and the adjacent host bone is not fully understood. This information has bearing on post-surgical...
Digital Image Correlation(DIC) is one of full-field strain measurement techniques devel- oped in recent decades, which has been well-demonstrated to conduct the mechanical properties study of solid materials, by collecting data using digital cameras. X-ray to- mography(CT) imaging helps the correlation techniques expanded to three dimensional investigation of materials, known...
Pedicle screw breakage and loosening remain as clinical complications of short segment instrumentation procedures for spinal stabilization. This study has directly visualized and measured elastic, plastic and total vertebral pedicle trabecular bone full-field strains in the regions immediately surrounding the pedicle screw during pedicle screw insertion by utilizing functional microCT...
Powder Bed Fusion (PBF) techniques are additive manufacturing (AM) technologies with paradigm-shifting potential for the production industry. However, before they can become viable production solutions for quality critical industries, issues with process consistency and repeatability need to be addressed. There is a need for in-situ sensing systems that characterize process...
Identifying material characteristics of composites is important in designing any
structural system. The aerospace industry relies on these material properties not only to
design a functional aircraft, but also a safe and reliable one. Since carbon fiber
composites are relatively new materials, little is known about its characteristics under
certain...
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Brian K. Bay
Identifying material characteristics of composites is important in
A large part of low-back pain occurrences are due to disc herniation or prolapse of the nucleus pulposus. An alternative technique to existing treatments of low back pain includes nucleus pulposus replacement by an artificial material to relieve pain and restore normal function. To date, there has been a deficiency...
Tibial stress fractures are common in runners. However, it is unclear what factors are associated with tibial stress fractures. This study aimed to investigate 1) magnitudes of bone contact forces occurring while running 2) whether or not repeated application of running loads is sufficient to explain tibial stress fractures and...
A measurement system has been developed to continuously record pressure data between the sole of the foot and the shoe. Five force sensing resistors are mounted to an insole suitable for shoe insertion. The sensors are located at the heel, toe and under three metatarsal heads. Data from the sensors...
In order to generate practical ways to easily design functional flexible lattice structures, this research seeks to find a way to predict reactive forces of compressed hyperelastic cubic lattice structures. Using 3D printed test coupons, material data was collected for use in finite element analysis. Cubic lattice structures with varying...
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BrianBay, Committee Member, representing School of Mechanical, Industrial, and Manufacturing
Due to their viscoelastic properties, polymers and hydrogels are widely used in many applications. In this study, the viscoelastic properties of elastomer polymers were investigated for a series of hydrogel, hydrogel composites and silicon materials. A primary application for hydrogels and hydrogel composites is as a replacement for the degenerated...
Renewable energy sources are becoming increasingly important due to their low environmental impact and limitless nature. This thesis explores the design of a 250 mW permanent magnet linear generator wave energy converter to power ocean sensors. While many wave energy converters exist, this is a unique application because the wave...
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...
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John A. Nairn & BrianBay
In many composites, fiber bridging develops as part of the
Degeneration of the intervertebral disc (IVD) is a phenomenon that has yet to be adequately addressed. Treatment options remain limited and incomplete. The ability to effectively cryopreserve IVDs would allow for better allograft transplantations and storage of samples for research purposes. This study aimed to assess how cryopreservation with different...
In anatomical education, clinicians, surgeons, and anatomists support the use of human cadavers over digital or artificial alternatives. Cadaver use raises the challenge of preventing tissue dehydration. The OSU cadaver labs attempt to maintain hydration by re-covering the exposed tissues with original skin, layers of plastic wrap, and/or towels and...
Metallic glasses (also referred to as amorphous metals) have been gaining interest in the materials science community in recent years. These amorphous materials demonstrate promising properties compared to their crystalline counterparts that include much higher strength and elastic strain limit, better corrosion and wear resistance, superior soft magnetism, and an...
Visitors to waterways need a way to securely lock up their non-motorized watercrafts to allow for exploration of the local area and communities. The Willamette Water Trail Steering committee recognized this problem and approached the Oregon State University Prototype Development lab to develop and fabricate a solution. The engineering design...
Flexible aerodynamic surfaces have been shown to favorably influence flight characteristics at low Reynolds numbers by increasing lift, angle of attack at stall, and resistance to perturbation. The objective of the research presented within this thesis is to investigate the influence of two aspects of flight observed in biological flyers,...
Driven by the need for high energy-density power sources, demand has
stimulated the development of small-scale engines. A small-scale engine
with a fuel supply could replace batteries and utilize higher energy-density
liquid hydrocarbon fuels; such an advance could deliver a new age of
portable devices. Currently, operable small-scale engines exist;...
The electrical conductivity data of ceramic material at high temperatures can be useful in the application of modeling, solid oxide fuel cell (SOFC), and magnetohydrodynamic (MHD). The existing data is considerably lacking at extreme temperatures. Our research focuses on bridging this gap by reporting the electrical conductivity measurements of sets...
As designers continue to develop the ability to improve a component or system design relative to any number of metrics, priorities and objectives, the need for advanced methodologies which focus efforts and steer design decisions to best meet the needs of the organization becomes increasingly important. This work develops such...
Chain saws are a common tool used by large logging corporations and family homesteads to manage forests, limb trees and buck lumber. A significant cost of operation is the continuous required supply of bar and chain oil. Consumers and logging corporations desire a lubricant with a high performance to cost...
Identifying material parameters in composite plates is a necessary first step in a variety of structural applications. For example, understanding the material parameters of carbon fiber composite is important in investigating sensor and actuator placement on micro-air-vehicle wings for control and wing morphing purposes. Knowing the material parameters can also...
The objective of this paper is to demonstrate a method for mechanically characterizing a 25 μm thick elastoviscoplastic hemodialysis membrane and for quantifying the force required to use that membrane in compression sealing. First, methods are developed for mechanically characterizing the thin elastoviscoplastic membrane. Then, a finite element model is...
The surgical standard of care to partially restore grasping function after a traumatic spinal cord injury is a reconstructive tendon transfer-surgery that connects all four finger flexors to an expendable wrist extensor. While restorative, this surgery has a fundamental problem; the movement of all four fingers flexors is directly coupled,...
Estuaries are once again emerging as important ecosystems for scientific study. Consequently, knowledge of what research has been conducted helps us identify benchmarks and plan new projects. A comprehensive bibliography of published research, technical reports, local documents, and data sets is one means of recording this knowledge. Yaquina Bay, located...
"The Marbled Murrelet (Brachyramphus marmoratus) is a small diving seabird of the Alcid family which is on the Federally Threatened Species list, and is state listed as endangered or threatened in California, Oregon, and Washington (Nelson, 1997). Because their nests are dispersed and difficult to locate high in trees of...
"The Marbled Murrelet (Brachyramphus marmoratus) is a small diving seabird of the Alcid family which is on the Federally Threatened Species list, and is state listed as endangered or threatened in California, Oregon, and Washington (Nelson, 1997). Because their nests are dispersed and difficult to locate high in trees of...
"The Marbled Murrelet (Brachyramphus marmoratus) is a small diving seabird of the Alcid family which is on the Federally Threatened Species list, and is state listed as endangered or threatened in California, Oregon, and Washington (Nelson, 1997). Because their nests are dispersed and difficult to locate within old forests on...
With growing concerns on environment impact of industrial product development, the product developers are seeking better solutions to achieve desired environmental benign requirements by the regulators and customers besides economic growth. During the last decade, some of the most successful product development companies (such as HP) have established their own...
Computing agents require state information to make coherent and useful decisions. A state representation is a numerical translation of the environment and conditions that are pertinent factors in an agent's decision making. Although many representations, when paired with clever learning algorithms, are able to coordinate and capture prey in specific...
Since the 1970s, tendon-transfer surgeries have been routinely performed for a variety of conditions such as stroke, paralysis, spinal atrophy, trauma, and birth defects. The surgery involves rerouting a tendon from a disabled muscle and directly suturing it to a functioning muscle in order to partially restore hand function. This...
A lightweight carbon fiber reinforced polymer (CFRP) c-channel beam was previously designed using analytical theory and finite element analysis and subsequently manufactured through a pultrusion process. Physical testing revealed the prototype did not meet the bending and torsional stiffness of the beam model. An investigation revealed that the manufactured prototype...
Airborne Wind Energy System (AWES) are quickly coming to fruition, with increased energy production while reducing the cost of implementation and materials. This thesis develops a new computational model for a tethered AWES and characterizes a new rapid prototyping method with the objective of supporting the design and rapid prototyping...
The use of adhesives in demanding engineering applications is a very common
occurrence in the modern world. These adhesives are taking the role of many traditional
fasteners, especially in the area of fiber reinforced composites. As the use of these
adhesives become more common place, better understanding of their mechanics...
Composites often are able to carry more load after damage due to the structure of laminates. In addition, damage can be difficult to detect in composites compared to homogeneous materials. Understanding the behavior of composite material after damage is vital for composite structural design. Currently, experimental methods exist for classifying...
Fiber reinforced polymers have gained considerable attention due to their wide range of applications, leading to significative concerns for end-of-life recyclability and disposal. Natural fibers and recycled carbon fibers, coupled with thermoplastic matrices can provide a sustainable and environmentally friendly alternative to traditional materials.
This study focused on experimental materials...
In order to solve some classic problems in traditional topology optimization, such as unknown material distribution, checker-boarding and curse of dimensionality, this thesis introduces a new method to construct a mechanical structure that can reduce mass and increase stiffness. It uses a graph to represent the skeleton of a structure....
Time-dependent crack growth mechanisms in Alloy 617 at 800°C in air were studied using compact tension samples machined in the L-T direction, cracked at temperature using an induction furnace and servo-hydraulic load frame. The application of different loading waveforms, including triangular, hold time, and sustained loading, were studied with relation...
Cutting operations using blades appear in several different industries such as food processing, surgical operations, gardening equipment, and so forth. As our society continues to increase our technological prowess, there is an ongoing need to better understand the underlying causes of simple tasks such as cutting so that cutting operations...
Among the many safety hazards facing chainsaw operators, the phenomenon known as kickback is the most dangerous. Kickback occurs when the chain at the tip of the chainsaw is caused to stop abruptly, and transfers the energy of the cutting chain to motion of the saw. The saw will rotate...
Biocompatible hydrogels composed of covalently crosslinked, chemically modified hyaluronan (HA), gelatin (Gtn), and heparin (Hp) were synthesized for controlled release of human vascular endothelial growth factor (VEGF) or basic fibroblast growth factor (bFGF). We hypothesized that inclusion of small quantities of heparin in these gels would result in regulated growth...
During four cruises in July and September of 2008 and 2009, the shipboard X-band radar was tuned to detect the modulated bands of surface roughness caused by converging and diverging currents associated with high-frequency nonlinear internal wave (NLIW) packets. The data collected was used to quantify the propagation direction (ϴp),...