Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Publication
Articles 1 - 19 of 19
Full-Text Articles in Entire DC Network
The Design Of A Multiple Position Turret For Changing Robot End Effectors, William Lang
The Design Of A Multiple Position Turret For Changing Robot End Effectors, William Lang
Theses
This paper discusses the design and build of a multiple position turret used to simultaneously attach six end effectors to a four-degree of freedom Adept robot. The main objective of this thesis is to develop a prototype tool changer that is different, more cost effective, and offers more features and versatility than any other. Use of the turret allows the robot to quickly change the end effector in use by simply rotating any of the others into the ready position. This reduces the tool changing time in a high-speed assembly process that is normally associated with conventional tool changers disconnecting …
An Investigation Of The Heat Transfer Suppression Mechanisms In The Pool Boiling Of Aqueous Solutions Of Ethylene Glycol, Lucas Alves
Theses
An experimental investigation of the heat transfer behavior of a binary system, whose constituents are water and ethylene glycol, is undertaken. The objectives of this study are: 1 . To conduct a comprehensive literature search. 2. To examine the effect of certain parameters on the heat transfer suppression mechanisms of binary systems. 3 . To gather new data for boiling heat transfer of aqueous ethylene glycol solutions, over the entire range of concentrations. The dilute concentration range, with solutions of 0.0 - 0. 1 mass fractions, is given special attention in clarifying what are the effects of surface tension, mass …
Lateral Guidance Control Of A Low-Speed Vehicle, Haydar Sahin
Lateral Guidance Control Of A Low-Speed Vehicle, Haydar Sahin
Theses
This thesis examines the lateral guidance control of a low-speed vehicle. Several topics are studied in detail: (1) vehicle error-state model for lateral guidance based on Ackerman steering and (2) lateral guidance control of a low-speed vehicle using fuzzy logic. Independently written research papers address each topic. The first paper presents a second order "error-state" kinematic model based on Ackerman steering appropriate for studying the lateral guidance control of low-speed vehicles traversing on roads of constant curvature. Lateral guidance control of vehicles is of great interest to the Advanced Vehicle Control Systems (AVCS) Division of the Intelligent Transportation System (ITS) …
Development Of A Dynamic Model For A Two Stage Servovalve Amplifier Line And Orifice, David Cook
Development Of A Dynamic Model For A Two Stage Servovalve Amplifier Line And Orifice, David Cook
Theses
Electrohydraulic servovalves are used in a variety of industrial, military, and aerospace applications. For some of these applications the servovalve must meet stringent dynamic performance criteria while under the influence of external disturbances. The most common of these external disturbances is vibration. Vibration can not only have an affect on valve performance, but can also affect valve stability. This thesis deals with the development of a dynamic model of the amplifier lines and line orifice of a two stage servovalve. The amplifier lines are thought to affect the stability of two stage servovalves under vibration. The amplifier lines are the …
Design, Development, And Performance Of A Transient Heat Transfer Resistance Fouling Monitor, David Gruszczynski
Design, Development, And Performance Of A Transient Heat Transfer Resistance Fouling Monitor, David Gruszczynski
Theses
Fouling can be defined as the formation of deposits on heat transfer surfaces that impede heat transfer and increase the resistance to fluid flow. The presence of fouling deposits result in the loss of equipment efficiency, the loss of equipment utilization, the requirement of additional capital expenditures, and adds the cost of cleaning to a process. The cost of fouling to all industries using heat exchangers in the United States was estimated to be 2 x 10+1 dollars per year in 1995. Thus, the control or mitigation of fouling is critical to all industries which employ heat transfer equipment. In …
An Experimental Method To Determine Micromechanical Properties Of Thin Films Using The Atomic Force Microscope, Brandon Comella
An Experimental Method To Determine Micromechanical Properties Of Thin Films Using The Atomic Force Microscope, Brandon Comella
Theses
A promising method has been developed to determine micromechanical properties of thin film materials. Metal and ceramic thin films are used extensively in the computer microprocessor industry and in the relatively new field of Micro- Electromechanical Systems (MEMS). The push for miniaturization and increased performance out of the computer microprocessor and MEMS devices have pushed materials to their limits. Micromechanical properties are very difficult to obtain due to the lack of adequate testing equipment on the microscale. The atomic force microscope (AFM), most commonly used as an imaging tool, lends itself to mechanical interaction with the sample surface by means …
Investigation Of The Effects Of Nosetip Shape In Terminal Ballistics Using A Wave Mechanics Model, Jack Scott Mcmurtry
Investigation Of The Effects Of Nosetip Shape In Terminal Ballistics Using A Wave Mechanics Model, Jack Scott Mcmurtry
Doctoral Dissertations
The purpose of this work is to delineate some of the physical mechanisms which govern the effect of nosetip shape on terminal ballistics phenomenology. A principal goal in the study of terminal ballistics has been the prediction of depth of penetration and crater diameter for penetrators and targets of various geometries, sizes, and materials. The model developed here is based on a "quasi-steady wave" mechanics approach to the problem with a 1-D model for the penetrator and a 2-D model for the target. The model is based on the application of the conservation of momentum equation to a control volume …
Finite Element Modeling Of A Moving Boundary Problem, Chang Heub Lee
Finite Element Modeling Of A Moving Boundary Problem, Chang Heub Lee
Theses
The analysis and calculation of the finite element modeling of a moving boundary between immiscible fluids in a porous medium is presented. One fluid is introduced under prescribed inlet boundary conditions and the motion of the resulting interface boundary studied and calculated. The aforementioned scenario is calculated using a finite element program based on the software, MATLAB. Analytical solutions developed in one dimension illustrate the moving boundary movement and benchmark for numerical solutions. The aim of computer aided calculation is to develop and predict a model applicable to a real situation, yet flexible enough for future adaptation to other problems …
An Experimental Determination Of Freeplay And Its Effect On Modal Complexity And Damping, Timothy S. Merle
An Experimental Determination Of Freeplay And Its Effect On Modal Complexity And Damping, Timothy S. Merle
Theses
This experiment is designed to address the effects of joint related nonlinearities on system parameters. Specifically, the effects of freeplay on the natural frequency, damping, and modal complexity. Many modal analysis techniques assume a system exhibits linear properties that are time invariant. Large structures are commonly constructed with several pinned and bolted joints and these joints can lead to gap and frictional-type nonlinearities. Joint nonlinearities will result in exaggerated damping estimates and complex time-varying mode shapes. These characteristics will result in incorrect modal parameter estimation when estimation assumes linearity. The experiment's intent is to examine nonlinearities and indicate methods of …
Design Optimization Of A Xerographic Auger System, Kip Jugle
Design Optimization Of A Xerographic Auger System, Kip Jugle
Theses
This thesis will show how the Taguchi technique can be applied to a complex system and can be optimized with a minimum number of tests. The focus of this thesis is the application of Taguchi methods to the optimization of a xerographic developer auger system. An auger system was optimized to minimize the toner concentration across the magnetic roll. By minimizing the toner concentration variation across the magnetic roll, the visual density variation on the customer prints can be minimized. The technique was applied by determining the proper control factors that can be used to minimize the variation of the …
A Study Of An Under Hood Automotive Air-Conditioning Component For The Purposes Of Noise And Vibration Reduction, Charles Depasquale
A Study Of An Under Hood Automotive Air-Conditioning Component For The Purposes Of Noise And Vibration Reduction, Charles Depasquale
Theses
All automotive components are engineered to be as quiet and smooth running as possible. This takes into account structure borne noise as well as air borne noise. A standard air conditioning compressor is analyzed statically (outof- vehicle testing) in this study to better understand noise and vibration traits. Mode shapes of the compressor, associated with noise, are extracted in an operating frequency range and shown to be modeled after a simple two degree of freedom system. Bearing free play in the pulley is cited as another possible source of noise. Lastly, with the use of theoretical damping, the sound pressure …
Analysis Of The Thermoelastic Response Of A Semi-Space To A Short Laser Pulse, Gary Renz
Analysis Of The Thermoelastic Response Of A Semi-Space To A Short Laser Pulse, Gary Renz
Theses
A study of the thermoelastic response of a semi-space medium to a short laser pulse generated heat is presented. This study uses the generalized thermoelasticity theory proposed by Green and Lindsay. This theory generalizes the classical theory of thermoelasticity by developing hyperbolic heat conduction equations and temperature-rate dependent constitutive equations. By so doing, an inherent paradox and physically unrealistic result in the classical theory of thermoelasticity that proposes infinite speed of thermal responses through a medium is corrected. Its validity is justified by the satisfaction of Fourier's law by which classical thermoelasticity is based. The Green-Lindsay theory adopts two thermal …
Valve Train Natural Frequency Measurement And Analysis, Cynthia Greene
Valve Train Natural Frequency Measurement And Analysis, Cynthia Greene
Theses
Natural frequencies are very important characteristics of a valve train system. From the measured natural frequencies of a valve train the following can be determined: will the system have acceptable dynamic behavior, is one valve train system design superior to another, and is a dynamic model of the system properly setup. The three most important modes of vibration of a valve train system are the fundamental mode of vibration of the entire linkage (system natural frequency), translation of the valve spring, and torsion of the camshaft. Valve trains are nonlinear systems due to varying system geometry throughout the lift event. …
Indenting Thin Films Using An Atomic Force Microscope, Cheryl O'Neal
Indenting Thin Films Using An Atomic Force Microscope, Cheryl O'Neal
Theses
The feasibility of using a Scanning Probe Microscope to measure nanomechanical properties of thin films was investigated. An Atomic force Microscope was utilized in an attempt to perform nanoindentations to measure the hardness and elastic modulus of several materials. A high modulus cantilever beam was constructed from silicon and a tungsten bead was adhered to its free end. Using this cantilever assembly three samples were indented: a bulk aluminum sample, a 2micrometers thick aluminum film sputtered onto a glass substrate, and a elastomer (rubber band). Subsequent to the indenting process, force curves were captured in the form of tip deflection …
The Use Of Axially Loaded Flexures For Vibration Isolation In The Omega Laser Facility Target Positioner, Lance Lund
The Use Of Axially Loaded Flexures For Vibration Isolation In The Omega Laser Facility Target Positioner, Lance Lund
Theses
The OMEGA Laser Facility is used for laser driven inertial confinement fusion research at the University of Rochester's Laboratory for Laser Energetics. This facility requires 1 millimeter diameter spherical targets placed at the center of an experimental chamber to remain stable to within 5 microns (0.0002"). Occasionally a mounted target will exceed this stability specification due to ambient vibration, so an isolation stage is proposed as a means of eliminating this problem. This isolation stage consists of six parallel flexures that are axially loaded to reduce the resonant frequency of the isolator. Frequency versus axial load, damping, and linearity are …
Two-Phase Flow In Microchannels, Roger Scott Stanley
Two-Phase Flow In Microchannels, Roger Scott Stanley
Doctoral Dissertations
The purpose of this study was to investigate fluid mechanic and heat transfer characteristics of two-phase two-component flow in rectangular microchannels. Experiments were conducted using rectangular aluminum channels with hydraulic diameters ranging between 56 $\mu$m and 256 $\mu$m and aspect ratios which varied from 0.5 to 1.5. Both single- and two-phase tests were conducted using water and gaseous argon, helium, and nitrogen as the working fluids. The Reynolds number for both types of experiments ranged from approximately 50 to nearly 10,000. The Nusselt number ranged between 0.0002 and 70. The single- and two-phase experimental data were empirically correlated, using parameters …
Vision Assisted Robotic Assembly Of Miniature Parts, Guy Vottis
Vision Assisted Robotic Assembly Of Miniature Parts, Guy Vottis
Theses
The objective of this thesis was to design and build a work cell that utilized a robotic vision system to assemble a micro motor. The work cell design consisted of an Adept SCARA robot with a vision system, end-of-arm tooling, and a combination work surface/ lighting system. On-screen vision tools were applied to images of the parts, both binary and gray scale, to assist in accurate part recognition. Using these images, retained by the vision system as reference, the robotic vision software was programmed to enable the robot to pick up the various parts in random positions within the cell …
Vibration Analysis Of A Diesel Engine Mounted On A Test Chassis, Quan Le
Vibration Analysis Of A Diesel Engine Mounted On A Test Chassis, Quan Le
Theses
This paper presents vibration analyses performed on a diesel engine mounted on a test chassis. Four methods were used in analyzing engine vibrations on the test chassis. Static engine vibration analysis was an experimental method used to identify natural engine frequencies and modes shapes on the test chassis. In this technique, the non-running engine was excited by an external input force. A running engine analysis was used to determine engine resonance frequencies. In this analysis, the engine was excited by the running dynamics of its components. Engine speeds at those resonance frequencies were also determined in this test. Thirdly, lumped …
Mechanics Of A Shear Cutting Process, Stephen Meissner
Mechanics Of A Shear Cutting Process, Stephen Meissner
Theses
A unique laboratory device, the Laboratory Shear, has been designed and built to simulate and examine the shear angle cutting process, which is the predominant method used in many cutting operations. The device is capable of force and velocity measurements of the shear angle cutting process with the abilities to vary cutting speed, knife preload, and blade geometry. The dimensions of the device are such that mobility to and from conditioning rooms in the laboratory environment are not limited. Assembly and disassembly ease as well as automatic versus manual operation options were incorporated for greater experimental flexibility. The device has …