A need exists to develop a non-destructive testing technique that can identify
the formation and propagation of diagonal tension cracks in conventionally
steel reinforced concrete deck girder (RCDG) highway bridges in the State of
Oregon. Such a technique could be included into a structural health
monitoring (SHM) system installed on...
A brake-based wheel speed control system for a rear-wheel drive vehicle is developed and simulated in this thesis. The OSU mini-Baja vehicle team will use this study in the development and implementation of a similar system for upcoming competitions. Vehicle submittals must differ to a specified degree from previous year’s...
Aquatic insect population counts can be a good indicator of the health, or water quality, of rivers and streams. Stoneflies (Plecoptera) are particularly susceptible to pollution in streams. However, today’s current method for obtaining these population counts requires biologists to examine individual specimens under a microscope for identification to the...
A distinct characteristic of legged locomotion is its periodic nature. This periodic motion, in the form of a periodic orbit, has been the target of many walking and running control strategies. The spring loaded inverted pendulum (SLIP) has become a popular model of sagittal plane locomotion, exhibiting behavior characteristic of...
Normal gait of human is believed to be an adapted motor control result of optimal behavior of individual. Normal gait would be altered by aging or injury without being perceived. Subtle changes in gait which is not easy to detect, can cause many serious problems including joint pains and even...
The droplet formation process in the vicinity of the nozzle exit and the behavior of a spreading droplet during impingement on a smooth glass surface were studied. Two nozzle geometries were tested. The first case was a stiff stainless steel nozzle plate 0.787 mm thick. The second case was a...
Extending the flight time of an autonomous unmanned air vehicle by soaring is
considered. A suboptimal controller is developed and successful static soaring is
demonstrated with a 6 degree of freedom glider model. Altitude gain rates of between
¼ and ½ m/s are achieved with this simple implementation.
A hybrid...
Product design is often driven by customer needs and desires. In this case the customer is the US military, and the desire is to have a cooling unit small enough and light enough to incorporate into hazard suits for use in desert combat. The Micro technology-based Energy and Chemical Systems...
Proper orthogonal decomposition (POD) in conjunction with the Galerkin projection has been used as a model reduction technique for the tractable real-time control of high-dimensional systems. While POD based model reduction may improve the tractability of high-dimensional models, the nonlinear POD based model may be impractical for control due to...
An experimental study of the near-field flow structure produced by an incompressible turbulent Acoustically Self-Excited Jet (ASEJ) in a large enclosure using Particle Image Velocimetry (PIV) is presented. The salient feature of this jet is that it provides an increase in near-field mixing and turbulence without additional external power input....
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...
For piezoelectric stack (PZT) driven droplet generator, the driving waveform
and driving frequency effect on liquid filament shape and droplet characteristics have
been experimentally studied. The experimental study was based on a PZT driven
droplet generator with known geometric design parameters and working fluid
properties. A lumped-element-model (LEM) constructed to...
It is crucial for the development of high quality products that design requirements are identified and clarified as early as possible in the design process. In many projects the design requirements and design specifications evolve during the project cycle. Shifting needs of the customer, advancing technology, market considerations and even...
An experiment was conducted to examine the possible impact of an engineering design and problem solving process overview document on knowledge management and capture. A process overview document was first created. Next, two multi-disciplinary design teams worked over a two-week span to develop concepts to address a problematic opportunity. One...
It is hypothesized that increases in pressure drop due to vapor generation during boiling in microchannels can be reduced by extraction of vapor at its point of inception. Ultimately, this local vapor extraction decreases the pressure drop required to drive the flow through a fractal-like branching, microchannel flow network within...
Oregon Department of Transportation’s bridge no. 9743b is a multi-span, two-girder steel deck bridge connecting the busy interstates 5 and 205. Vertical cracks have been detected in the welded girder-to-crossbeam connections at the bents. Distortion-induced fatigue is suspected to be responsible for the cracking. Linear elastic beam analysis, 2-D and...
Air travel presents several problems for passengers with disabilities.
One in particular is how they get from their wheelchair and to an aircraft seat.
The commonly used manual transfer method is hazardous to the assistants
and the passenger. There are other alternatives, but they have plenty of room
for improvement....
An experimental study of absorption of ammonia into a constrained thin film of ammonia-water solution is presented. A large aspect ratio microchannel with one of its walls formed by a porous material is used to constrain the thickness of the liquid film. Experiments were performed at a pressure of 1,...
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;...
Droplet formation from a flexible nozzle plate driven by a prescribed-waveform excitation of a piezoelectric is numerically investigated using a computational fluid dynamics (CFD) model with the VOF method. The droplet generator with a flexible nozzle plate, which is free to vibrate due to the pressure acting on the plate,...