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Filtering by: Creator Cowles, Timothy J. Remove constraint Creator: Cowles, Timothy J. Academic Affiliation Mechanical Engineering Remove constraint Academic Affiliation: Mechanical Engineering

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  • Investigation of combustor and fuel preparation requirements for a combined-cycle wood fired power plant

    Creator:
    Bauer, Timothy Lee
    Abstract:
    The Pacific Northwest is a particularly good candidate for a power plant fired with wood since the wood products industry is so important in the area. The combined cycle concept for such a plant has increased in popularity due to the generally greater efficiency of the gas turbine part of...
    Resource Type:
    Masters Thesis
    Full Text:
    requirements for a combined-cycle wood fired power plant AN ABSTRACT OF THE THESIS OF Timothy Lee Bauer for

  • Natural convection from a horizontal cylinder parallel to a heated vertical wall

    Creator:
    McCoy, Timothy J.
    Abstract:
    Heat transfer measurements have been made from a long (L/D = 15) horizontal cylinder in water parallel to a heated vertical wall. The cylinder and wall boundary conditions were isothermal, and they were maintained at equal temperatures. The investigation covered Rayleigh numbers based on cylinder diameter from 400,000 to 10,000,000....
    Resource Type:
    Masters Thesis
    Full Text:
    AN ABSTRACT OF THE THESIS OF Timothy J. McCoy for the degree

  • Using discrete-event simulation to study the influence of log yard sorting on sawmill processing efficiency of small-diameter timber

    Creator:
    Pinon, Olivia J.
    Abstract:
    A sawmill is similar to other manufacturing enterprises when it comes to making decisions, scheduling production and meeting customer demands. In order to help sawmills achieve their goals, and because there is such a high degree of variability in the raw material used in this industry, computer simulation has proven...
    Resource Type:
    Masters Thesis
    Full Text:
    AN ABSTRACT OF THE THESIS OF Olivia J. Pinon for the degree of

  • Three-dimensional, nonlinear viscoelastic analysis of laminated composites : a finite element approach

    Creator:
    Wang, Min
    Abstract:
    Polymeric composites exhibit time-dependent behavior, which raises a concern about their long term durability and leads to a viscoelastic study of these materials. Linear viscoelastic analysis has been found to be inadequate because many polymers exhibit nonlinear viscoelastic behavior. Classical laminate theory is commonly used in the study of laminated...
    Resource Type:
    Dissertation
    Full Text:
    : Timothy C. Kennedy Polymeric composites exhibit time-dependent behavior, which raises a concern about

  • A study of cavitation instabilities in solids

    Creator:
    Puttapitukporn, Tumrong
    Abstract:
    Cavitation instabilities in elastic-plastic solids under spherically-symmetric and axisymmetric loadings were investigated using the finite element method. Both quasi-static and dynamic analyses were used to solve these problems. In the quasi-static analyses, we investigated a cavitation instability in elastic/perfectly-plastic, linear hardening elastic-plastic, power hardening elasticplastic, and constrained silver materials. Here,...
    Resource Type:
    Dissertation
    Full Text:
    Cavitation Instabilities in Solids. Abstract anoroved: Timothy C. Kennedy Cavitation instabilities in

  • A nonlocal damage theory for laminated plate with application to aircraft damage tolerance

    Creator:
    Nahan, Matthew F.
    Abstract:
    Design of commercial aircraft structure, composed of composite material, requires the prediction of failure loads given large scale damage. In particular, a fuselage of graphite/epoxy lamination was analyzed for damage tolerance given a standard large crack that severed both skin and internal structure. Upon loading, a zone of damage is...
    Resource Type:
    Dissertation
    Full Text:
    : Timothy C. Kennedy Design of commercial aircraft structure, composed of composite material, requires the

  • A study of forces on simulated heat exchange tubes immersed in a cold fluidized bed

    Creator:
    Donovan, Jerry Eugene
    Abstract:
    The object of this research, project was to study how different parameters effect the magnitude and frequency composition of forces exerted on simulated heat exchange tubes immersed in a cold fluidized bed. Two arrays of tubes were assembled with the tubes mounted in an equilateral triangular pitch pattern. The center...
    Resource Type:
    Masters Thesis
    Full Text:
    HEAT EXCHANGE TUBES IMMERSED IN A COLD FLUIDIZED BED Abstract approved: Redacted for Privacy (Timothy

  • Micromechanics of heterogeneous materials under compressive loading

    Creator:
    Laird, George
    Abstract:
    In mining and mineral processing, compressive loading is often encountered during the comminution of ore bearing minerals and in the wear resistant materials used in the comminution circuit. A common thread joining many of the materials that are primarily used under compressive loading is the presence of a high modulus...
    Resource Type:
    Dissertation
    Full Text:
    Many thanks go to my major advisor, Dr. Timothy C. Kennedy for his thoughtful advice and encouragement

  • Simulating changing diameter distributions in a softwood sawmill

    Creator:
    Salichon, Maxence C.
    Abstract:
    Sawmills are very complex systems that involve many manufacturing processes. The variability of their raw material adds further to this complexity as each log has characteristics that determine its processing path. Therefore, computer simulation is a very useful technique for analyzing sawmill performance. This thesis describes a simulation computer model...
    Resource Type:
    Masters Thesis
    Full Text:
    professors, Dr. Charles C Brunner and Dr. Timothy C. Kennedy for their invaluable support, assistance and

  • Development of acoustic emissions testing procedures applicable to conventionally reinforced concrete deck girder bridges subjected to diagonal tension cracking

    Creator:
    Lovejoy, Steven C.
    Abstract:
    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...
    Resource Type:
    Dissertation
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    : Timothy C. Kennedy A need exists to develop a non-destructive testing technique that can identify

  • Experimental and finite-element analysis of stress distributions near the end of reinforcement in partially reinforced glulam

    Creator:
    Kirlin, Chad P.
    Abstract:
    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...
    Resource Type:
    Masters Thesis

  • Transient fuel pin temperature calculations using describing functions

    Creator:
    Guidotti, Timothy E.
    Abstract:
    An important element in rector safety and fuel performance assessments is the efficient calculation of the time dependent temperature profiles within reactor fuel pins. Because the fuel pins have temperature dependent thermal properties, the governing partial differential equations are nonlinear. Traditionally, finite difference or finite element methods have been used...
    Resource Type:
    Masters Thesis
    Full Text:
    describing functions AN ABSTRACT OF THE THESIS OF Timothy E. Guidotti for the degree of Master of Science

  • Turbulence induced loads on a teetered rotor

    Creator:
    Weber, Timothy L.
    Abstract:
    Development of variable speed horizontal axis wind turbines has resulted in a need for an analysis code with a rotor speed degree-of-freedom. This study develops a five degree-of-freedom time domain computer code that evaluates blade and rotor, mean and cyclic loads with nonlinear aerodynamics together with atmospheric turbulence as a...
    Resource Type:
    Dissertation
    Full Text:
    OF THE THESIS OF Timothy L. Weber for the degree of Doctor of Philosophy in Mechanical Engineering

  • Response of guyed offshore towers to stochastic loads in the presence of steady current

    Creator:
    Brynjolfsson, Sigurdur
    Abstract:
    The validity of the widely used stochastic linearization method for analysing the response of guyed towers to stochastic loads is investigated. The governing equations of a guyed tower have two main sources of nonlinearities, fluid-structure interaction and the restoring force of the cables. In this study, two models are considered....
    Resource Type:
    Dissertation
    Full Text:
    : / Dr. John W. Leonard Redacted for Privacy Dr. Timothy C. Kennedy The validity of the widely used

  • Elastodynamic analysis of a propagating finite crack in a micropolar elastic solid

    Creator:
    Han, Seog-young
    Abstract:
    A dynamic propagation of a finite crack of opening mode in a micropolar elastic solid was investigated. By using an integral transform method, a pair of twodimensional singular integral equations governing stress and couple stress was formulated in terms of the displacement transverse to the crack, macro- and microrotations, and...
    Resource Type:
    Dissertation
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    Reserved ACKNOWLEGEMENT I would like to express my appreciation to Dr. Timothy C. Kennedy and Dr

  • An experimental study of natural convection from protruding arrays on a vertical plate with and without an opposing wall for various fluids

    Creator:
    Lin, Peng-cheng
    Resource Type:
    Dissertation
    Full Text:
    Abstract approved: /Dwight J. Bushnell Natural convection from six rectangular protruding heated arrays

  • A study of compression loading of composite laminates

    Creator:
    Berbinau, Pierre J.
    Abstract:
    The compressive behavior of continuous fiber composites is not as well understood as their tensile behavior because research and industrial applications have until recently focused on the latter. Furthermore, most theoretical and experimental studies on the compression of composites have examined the case of unidirectional specimens with fibers along the...
    Resource Type:
    Dissertation
    Full Text:
    ABSTRACT OF THE THESIS OF Pierre J. Berbinau for the degree of Doctor of Philosophy in Mechanical

  • Distortion-induced fatigue cracking of girder-to-crossbeam connection

    Creator:
    Aljutaili, Dhari S.
    Abstract:
    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...
    Resource Type:
    Masters Thesis
    Full Text:
    Appendix B. The end moment is expressed as 2 16 .o PLM EI J = (4.2) where 3 3 3 3 2 xb

  • Quality driven collaborative decision making for product development under the influence of trustworthiness

    Creator:
    Meier, Stefan
    Abstract:
    The focus of this study is the effective prioritization of customer requirements in collaborative product development. The CR priorities are often retrieved by questioning and interviewing targeted customers. But the targeted customer might not always be easily questioned, because they might not always be obvious or clearly known. If customers...
    Resource Type:
    Masters Thesis
    Full Text:
    this thesis. The author also thanks Dr. Timothy C. Kennedy and Dr. Michael H. Freilich, who both

  • Evaluating the effectiveness of interaction strategies between product developer and supply chain using activity based modeling in environmental benign product design

    Creator:
    Wang, Bo
    Abstract:
    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...
    Resource Type:
    Masters Thesis
    Full Text:
    we all live far away from our parents. Also, thank Dr. Timothy C. Kennedy and Dr. Brian Bay to

  • The application of a band variable-inertia flywheel to an urban transit bus

    Creator:
    Moosavi-Rad, Hamid
    Abstract:
    This dissertation investigates by means of computer simulation the potential of a Band Variable-Inertia Flywheel (BVIF) to store energy for an urban transit bus. Replacing both a fixed-inertia flywheel (FIF) and a continuously variable transmission (CVT), the Band Variable-Inertia Flywheel is capable of accelerating a vehicle from rest to a...
    Resource Type:
    Dissertation
    Full Text:
    Professor Charles E. Smith for his support and assistance in this project; and Professors Timothy C

  • Automating aquatic insect identification through pattern recognition

    Creator:
    Thomas, Joshua K.
    Abstract:
    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...
    Resource Type:
    Masters Thesis

  • Composite and adhesive technology applied to chain saw guide bars

    Creator:
    Gabel, Preston S.
    Abstract:
    Increased competition in the market place for both occasional and professional chain saw users has led to a desire for improved performance in chain saw guide bars. One aspect of improved performance is lower bar weight. The primary focus of this research was to establish the feasibility of a lower...
    Resource Type:
    Masters Thesis
    Full Text:
    Istok, Dr. Timothy Kennedy and Dr. Skip Rochefort, I offer my most sincere thanks. A special thanks

  • Creep of Gr/BMI composite laminates in compression

    Creator:
    Tyagi, Sanjeev R.
    Abstract:
    The main source of the time-dependent behavior of fiber-reinforced composites is their polymeric matrix, which causes concerns about their long term durability. Although for composites where organic fibers such as Graphite are used, the fibers are also a contributing factor. A composite material may exhibit an appreciable amount of creep,...
    Resource Type:
    Masters Thesis
    Full Text:
    program. I would like to thank Dr. Timothy C. Kennedy, Dr. David G. Ullman and Dr. Rasaratnam Logendran

  • Wind turbulence input model for horizontal axis wind turbines

    Creator:
    Lin, Shuh-ren
    Abstract:
    In order to estimate wind turbine residL2;characteristics in the presence of atmospheric turbulence, the important atmospheric sources for the force excitations felt by the wind turbine system must be identified and characterized. The goal of this research is to develop the wind turbulence input model for horizontal axis wind turbines....
    Resource Type:
    Dissertation
    Full Text:
    . F. Tom Lindstrom, Dr. Timothy C. Kennedy, and Dr. Alan Robinson for taking their time to serve on

  • Mechanics of Nb-Ti superconducting composites

    Creator:
    Guo, Zhiqiang
    Abstract:
    Mechanical behavior of Nb-Ti superconducting composites with copper matrices have been studied experimentally and theoretically. Experimental work includes extensive measurements of Cu/Nb-Ti composite system. Techniques for fine fiber testing and composite wire measurement have been developed. Experimental parameters examined in this research include geometry, hardness, Young's modulus, Poisson's ratio, yield...
    Resource Type:
    Dissertation
    Full Text:
    Peterson, Timothy C. Kennedy, E. G. Wolff, and Dan Schafer for their kind advices and encouragements as

  • Residual strength properties of Gr/BMI composite laminates after constant/cyclic compression

    Creator:
    Shenoy, Krishnananda
    Resource Type:
    Masters Thesis
    Full Text:
    would like to thank Dr. Timothy C. Kennedy, Dr. Jun Koike and Dr. Stephen W. Hoag for their time and

  • On the lyapunov-based approach to robustness bounds

    Creator:
    Jo, Jang Hyen
    Abstract:
    The objective of this investigation is the development of improved techniques for the estimation of robustness for dynamic systems with structured uncertainties, a problem which was approached by application of the Lyapunov direct method. This thesis considers the sign properties of the Lyapunov function derivative integrated along finite intervals of...
    Resource Type:
    Dissertation
    Full Text:
    committee members, Drs. Eugene F. Fichter, Timothy C. Kennedy and Tom M. West for their advice and

  • Mechanical characterization of a simple gel in a prototype device that models a degenerative intervertebral disc

    Creator:
    Cenar, Yannick
    Abstract:
    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...
    Resource Type:
    Masters Thesis

  • Large-strain softening of aluminum in shear at elevated temperature

    Creator:
    Alhajeri, Saleh N.
    Abstract:
    Pure aluminum deformed in torsion (shear) at elevated temperatures reaches a broad "peak" stress and then undergoes about a 17% decrease in flow stress with deformation to roughly 1-2 equivalent uniaxial strain. Beyond this strain the flow stress is approximately constant. The sources for this softening are unclear. The suggested...
    Resource Type:
    Masters Thesis
    Full Text:
    . Timothy C. Kennedy, Dr. William H. Wames, and Dr. R. Logen Logendran. I appreciate their time investment

  • Derivation and automatic generation of Kane's dynamical equations for mechanical manipulators

    Creator:
    Nie, Tinglin
    Abstract:
    To design and precisely control a manipulator requires developing an efficient dynamic model of the system. The present work demonstrates how this can be accomplished by employing Kane's dynamical equations. First, a detailed manual derivation of the equations of motion for a particular robot is presented in such way that...
    Resource Type:
    Dissertation
    Full Text:
    . Appreciation is also extended to the members of my Ph.D committee, Dr. Robert E. Wilson, Dr. Timothy C

  • Transient nonlinear deformations of viscoelastic membranes

    Creator:
    Jenkins, Christopher H. M.
    Resource Type:
    Dissertation
    Full Text:
    possible. Thanks are also due to other members of my committee: Dr. Clarence A. Calder, Dr. Timothy C

  • Numerical study of natural convection in square partitioned and non-partitioned enclosures

    Creator:
    Sukkaset, Prasart
    Abstract:
    Heat transfer characteristics and associated temperature and flow fields for natural convection in two-dimensional, square, partitioned and non-partitioned enclosures have been determined for Grashof numbers ranging from 10³ to 10⁶. The vertical side walls of the enclosure are isothermal with all other surfaces assumed to be adiabatic. An adiabatic partition...
    Resource Type:
    Dissertation
    Full Text:
    , Professor Charles E. Smith, Professor Timothy C. Kennedy and Professor Harold I. Laursen, for their time

  • Robust controller design for robotic manipulators with saturation

    Creator:
    Liang, Zuyang
    Abstract:
    The development of modern industries calls for the robotic manipulators with high speed and accurate tracking performance. Many authors have paid attention to robust control of robotic manipulators; however, only few authors have also considered the control problem of manipulators with power limitation. In this dissertation, the robotic manipulator is...
    Resource Type:
    Dissertation
    Full Text:
    . Charles E. Smith, Prof. Timothy C. Kennedy, Prof. Alan H. Robinson and Prof. David G. Ullman for their

  • Nonlinear adaptive control of highly maneuverable high performance aircraft

    Creator:
    Cho, Sul
    Abstract:
    This thesis presents an effective control design methodology using a one-step-ahead prediction adaptive control law and an adaptive control law based on a Lyapunov function. These control law were applied to a highly maneuverable high performance aircraft, in particular, a modified F/A-18. An adaptive controller is developed to maneuver an...
    Resource Type:
    Dissertation
    Full Text:
    my committee members, Dr. W. Kolodziej, Dr. Timothy C. Kennedy, Dr. Robert E. Wilson, and Dr

  • Processing of laser interferometric signals for small displacement measurements

    Creator:
    Peng, Gwo-sheng
    Abstract:
    Algorithms for analyzing laser interferometry signals were developed and adopted to the computer based processing of small displacement measurements. These methods, matrix operation approach and fixed parameters approach, are based on signal phase calculation and are able to replace complex fringe counting electronic circuits. The matrix operation provides an approach...
    Resource Type:
    Dissertation
    Full Text:
    . Thomas K. Plant, Dr. Timothy C. Kennedy and Dr. William H. Warnes for reviewing the dissertation and

  • Drilling process evaluation by predicting drilled hole quality and drill bit wear with on-line acoustic emission signals

    Creator:
    Wang, Kuang-Jen, 1962-
    Abstract:
    Improvement of manufacturing productivity is dependent on the successful automation of manufacturing processes, the success of which is based in turn upon the availability of information which describes the state of manufacturing operations. Acoustic Emission (AE) signals related to the cutting process and tool wear have been recently applied to...
    Resource Type:
    Dissertation
    Full Text:
    . Smith, Timothy C. Kennedy, and Michael R. Milota, for their interest and support. Thanks are also

  • Thermal energy recovery from large transformers

    Creator:
    Yao, Barry
    Abstract:
    This thesis is concerned with designing and simulating waste energy retrieval systems from large transformers to provide heating and cooling of a control house. The transformer selected is Transformer Bank One at the Ross Substation in the BPA system. The unit is an ASEA 250 MVA transformer with forced oil,...
    Resource Type:
    Masters Thesis
    Full Text:
    Pierce and Mr. Timothy Tong in accomplishing this project. TABLE OF CONTENTS I INTRODUCTION 1 II

  • Discrete-time explicit model reference adaptive control for robotic manipulators

    Creator:
    Yuh, Junku
    Abstract:
    In this dissertation a direct approach to discrete-time model reference adaptive control (MRAC) based on hyperstability theory is proposed to control industrial robotic manipulators. For industrial robots and manipulators, which usually have highly nonlinear and complex dynamic equations and often have unknown inertia characteristics, it is very difficult to achieve...
    Resource Type:
    Dissertation
    Full Text:
    years at OSU. It is pleasure to thank Dr. Timothy C. Kennedy for his encouragement, and Dr. Harold I

  • Analysis of a wood-fueled trimburner system for use in a combined-cycle, wood-fired power plant

    Creator:
    Stephenson, Jerry D.
    Abstract:
    This report investigates the use of wood to fuel a trimburner incorporated in a combined-cycle, biomass-fired power plant. The term "trimburner" applies to a ductburner which is designed to boost the temperature of the air stream entering the gas turbine. The work presented here is part of a larger biomass...
    Resource Type:
    Masters Thesis
    Full Text:
    Engineering in charge of major Redacted for Privacy Head of Department of Mechanleal Engineering j Redacted

  • Dynamics and control of a rigid/flexible manipulator

    Creator:
    Yeh, Chun-tien
    Abstract:
    Control of high-speed, light-weight robotic manipulators is a challenge because of their special dynamic characteristics. In this work, a two-stage control algorithm for the position control of flexible manipulators is proposed. First, the more complex, flexible robot system is replaced by a simplified hypothetical rigid body system (HRRA) with off-line...
    Resource Type:
    Dissertation
    Full Text:
    would not have been possible. I would also like to express my sincere appreciation to Dr. Timothy C

  • Quantitative comparison of full field strains experimentally measured and analytically predicted for aluminum foams

    Creator:
    Rutschman, Scott A.
    Abstract:
    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...
    Resource Type:
    Masters Thesis
    Full Text:
    providing the constitutive model and modeling advice Dr. Timothy Kennedy for his assistance in implementing

  • A model reference adaptive system for control of a flexible mechanical manipulator

    Creator:
    Lee, Byeung Kyun
    Abstract:
    For control of a flexible manipulator, the assumed- mode method is applied to the mathematical model of the model reference adaptive system. In the assumed-mode method, the flexible, continuous manipulator is described by a limited number of degrees of freedom. A modified model reference adaptive system is studied for direct...
    Resource Type:
    Dissertation
    Full Text:
    project. I would also like to express my sincere appreciation to Dr. Ronald B. Guenther and Dr. Timothy

  • Strain rate sensitivity index of thermoplastics from variable strain rate and stress relaxation testing

    Creator:
    Goble, David Leroy
    Resource Type:
    Masters Thesis
    Full Text:
    from the relation m = [aln(P)]/[aln(-P)]e j for these data. A marked lack of correlation of strain