Mechanical Engineering Commons^™

The Tlc Method For Modeling Creep Deformation And Rupture, David May

HIM 1990-2015

This thesis describes a novel new method, termed the Tangent-Line-Chord (TLC) method, that can be used to more efficiently model creep deformation dominated by the tertiary regime. Creep deformation is a widespread mechanical mode of failure found in high-stress and temperature mechanical systems. To accurately simulate creep and its effect on structures, researchers utilize finite element analysis (FEA). General purpose FEA packages require extensive amounts of time and computer resources to simulate creep softening in components because of the large deformation rates that continuously evolve. The goal of this research is to employ multi-regime creep models, such as the Kachanov-Rabotnov …

Scalable Nano Particle Production Of Low Bioavailability Pharmaceuticals For Augmented Aqueous Solubility, Aaron Madden

HIM 1990-2015

The billion dollar pharmaceutical research and development pipeline suffers greatly from high attrition rates of novel therapeutic compounds within pre-clinical and clinical trials. Poor bioavailability in many new drugs, originating in the various methodologies of high throughput screening, may explain part of these growing failure rates. One interpretation of this phenomenon relies on bioavailability's correlation with aqueous solubility; much modern processing allows chemicals to fully develop without touching water, yielding upwards of 90% of new chemical entities practically insoluble in aqueous media. Thus, one approach to alleviating bioavailability and potentially clinical attrition rates necessitates augmented aqueous solubility. The amorphous nanoparticle …

Kinesthetic Haptics Sensing And Discovery With Bilateral Teleoperation Systems, Tian Qiu

Doctoral Dissertations

In the mechanical engineering field of robotics, bilateral teleoperation is a classic but still increasing research topic. In bilateral teleoperation, a human operator moves the master manipulator, and a slave manipulator is controlled to follow the motion of the master in a remote, potentially hostile environment. This dissertation focuses on kinesthetic perception analysis in teleoperation systems. Design of the controllers of the systems is studied as the influential factor of this issue. The controllers that can provide different force tracking capability are compared using the same experimental protocol. A 6 DOF teleoperation system is configured as the system testbed. An …

Modeling, Analysis, And Control Of A Mobile Robot For In Vivo Fluoroscopy Of Human Joints During Natural Movements, Matthew A. Young

Doctoral Dissertations

In this dissertation, the modeling, analysis and control of a multi-degree of freedom (mdof) robotic fluoroscope was investigated. A prototype robotic fluoroscope exists, and consists of a 3 dof mobile platform with two 2 dof Cartesian manipulators mounted symmetrically on opposite sides of the platform. One Cartesian manipulator positions the x-ray generator and the other Cartesian manipulator positions the x-ray imaging device. The robotic fluoroscope is used to x-ray skeletal joints of interest of human subjects performing natural movement activities. In order to collect the data, the Cartesian manipulators must keep the x-ray generation and imaging devices accurately aligned while …

Strain-Based Design Methodology Of Large Diameter Grade X80 Linepipe, Mark D. Lower

Doctoral Dissertations

Continuous growth in energy demand is driving oil and natural gas production to areas that are often located far from major markets where the terrain is prone to earthquakes, landslides, and other types of ground motion. Transmission pipelines that cross this type of terrain can experience large longitudinal strains and plastic circumferential elongation as the pipeline experiences alignment changes resulting from differential ground movement. Such displacements can potentially impact pipeline safety by adversely affecting structural capacity and leak tight integrity of the linepipe steel.

Planning for new long-distance transmission pipelines usually involves consideration of higher strength linepipe steels because their …

Transport Resistance In Polymer Electrolyte Fuel Cells, Jon Patrick Owejan

Doctoral Dissertations

Fuel cells offer the potential for high efficiency energy conversion with only water and heat as significant products of the electrochemical reaction. For a cost-competitive product, fuel cell researchers are exploring the limits of the Pt catalyst loading in parallel with performance and durability trade-offs. A significant portion of the performance loss in low-cost PEMFCs is associated with the partial pressure of oxygen (for an air cathode) at the Pt surface. This dissertation explores the main components of oxygen transport resistance which are associated with diffusion through partially saturated porous media and the ionomer coating in the catalyst layer.

Under …

A Study Of Indentation Cracking In Brittle Materials Using Cohesive Zone Finite Elements, Kurt E. Johanns

Doctoral Dissertations

Cohesive zone finite element simulations of pyramidal indentation cracking in brittle materials have been carried out in order to: (1) critically examine indentation cracking models that relate fracture toughness to indentation data; (2) determine the underlying physical mechanisms of indentation crack growth from a continuum view and their relationship to material properties; (3) explore the influence of indenter geometry on crack extension; and (4) provide a platform from which future simulations can add more complex material behavior as well as guidance for experimental measurements of fracture toughness. Standard fracture toughness geometries in addition to simplified indentation geometries were simulated in …

Thermal Hydraulic Characteristics Of Fuel Defects In Plate Type Nuclear Research Reactors, Isaac Thomas Bodey

Doctoral Dissertations

Turbulent flow coupled with heat transfer is investigated for a High Flux Isotope Reactor (HFIR) fuel plate. The Reynolds Averaged Navier-Stokes Models are used for fluid dynamics and the transfer of heat from a thermal nuclear fuel plate using the Multi-physics code COMSOL. Simulation outcomes are compared with experimental data from the Advanced Neutron Source Reactor Thermal Hydraulic Test Loop. The computational results for the High Flux Isotope Reactor core system provide a more physically accurate simulation of this system by modeling the turbulent flow field in conjunction with the diffusion of thermal energy within the solid and fluid phases …

Bellevue-Santa Fe Charter School Solar Panel Project, Dulce Arroyo Martinez, Henrik Lee, Moises Quiroz, Timothy Iafrate

Mechanical Engineering

This project covers the design, manufacture, and installation of solar panel frames on a charter school in Avila Beach, CA. Through preliminary research regarding important factors (such as solar movement, ideal panel angle, and site-specific factors), a frame that meets the standards set forth in the California Building Codes was designed. After approval by presiding authorities, parts specified in the design were ordered, inspected upon arrival, and manufactured to the design as necessary. Much of the challenge was related to the installation aspect of the project—coordination with the proper authorities and correct submission of applications was integral to the success …

Effect Of Processing Parameters And Matrix Shrinkage On Porosity Formation During Synthesis Of Metal Matrix Composites With Dual-Scale Fiber Reinforcements Using Pressure Infiltration Process, Reihaneh Etemadi

Theses and Dissertations

This is first such study on porosity formation phenomena observed in dual-scale fiber preforms during the synthesis of metal matrix composites (MMCs) using the gas-based pressure infiltration process (gas PIP). In this thesis, different mechanisms of porosity formation during pressure infiltration of Al-Si alloys into Nextel's 3D woven ceramic-fabric reinforcements (a dual-porosity or dual-scale porous medium) are studied. The effect of processing conditions in terms of the infiltration temperature and pressure on porosity content of the ceramic fabric infiltrated by the alloys through the gas PIP is investigated. Relative density (RD), defined as the ratio of the actual MMC density …

Wetting, Superhydrophobicity, And Icephobicity In Biomimetic Composite Materials, Vahid Hejazi

Theses and Dissertations

Recent developments in nano- and bio-technology require new materials. Among these new classes of materials which have emerged in the recent years are biomimetic materials, which mimic structure and properties of materials found in living nature. There are a large number of biological objects including bacteria, animals and plants with properties of interest for engineers. Among these properties is the ability of the lotus leaf and other natural materials to repel water, which has inspired researchers to prepare similar surfaces. The Lotus effect involving roughness-induced superhydrophobicity is a way to design nonwetting, self-cleaning, omniphobic, icephobic, and antifouling surfaces. The range …

Phase Transformation In Monolayer Molybdenum Disulphide With And Without Defects Under Tension Predicted By Atomistic Simulations, Khanh Quoc Dang

Graduate Theses and Dissertations

In addition to its use as a solid lubricant, molybdenum disulphide (MoS2) has gained recent attention as a possible substitute for silicon as it is increasingly difficult to keep shrinking down electronic devices made of silicon, the conventional electronic material. When thinned down to atomic thickness, monolayer MoS2 possesses very unique and promising electronic and electrical properties. Unlike electronic and electrical properties, knowledge of the mechanical properties and role of structural defects on these properties of monolayer MoS2 is unexplored. For this thesis, the two main objectives are (1) to gain insight about the failure mechanism of monolayer MoS2 by …

Assortment Planning Of Automotive Products: Considerations For Economic And Environmental Impacts Of Technology Selection, Ali Taghavi, Ratna Babu Chinnam

Industrial and Systems Engineering Faculty Research Publications

A manufacturer’s assortment is the set of products that the company offers to its customers. Assortment planning considerably affects both the sales revenue and product offering costs for the company and it had experienced growing attention across different industries over recent decades. In this study, we propose a modeling framework that seeks to identify the optimal assortment for a manufacturer of configurable products (in particular, automobiles). Our model accounts for environmental considerations (Corporate Average Fuel Economy requirements, tail-pipe emissions, and greenhouse gas emissions related to the production of the fuel used to power the vehicle) during assortment planning. We formulate …

Development Of Nhtsa’S Side Impact Test Procedure For Child Restraint Systems Using A Deceleration Sled : Part 2, Janet Brelin-Fornari, Sheryl Janca

Mechanical Engineering Grants

This report presents the results of the continued research and development of child seat side impact tests using the deceleration sled at Kettering University’s Crash Safety Center. The objective of this test series was to gain further insight into the sensitivity of the side impact test fixture response. Test variations included speed of impact, weight of the fixture, and impact characteristics. Additionally, 20 child restraint system (CRS) specific tests were conducted using a fixed set of test parameters.

A Study On The Fluorescent Properties Of Nanoapatite Particles Under Externally Applied Magnetic Fields, Heidi Reid

TECHxpo

Hydroxyapatite is a naturally occurring mineral found in human bones and teeth. Its chemical formula is: Ca₁₀(PO₄)₆(OH)₂. In this project hydroxyapatite nanoparticles were doped with iron or europium to give the particles magnetic or fluorescent properties, respectively. The magnetic and fluorescent responses of these particles under externally applied magnetic fields has not yet been fully characterized.

Investigation Of Boiling Performance Of Graphene-Coated Surfaces, Daniel C. Stack

Honors Capstone Projects - All

In this Capstone Project, I sought to investigate the boiling performance of graphene-coated surfaces. Boiling was accomplished in a pool boiling chamber, with samples of graphene-coating SiO₂ wafers. I developed a procedure for graphene transfer for sample fabrication. Samples were prepared with graphene grown on copper substrates by chemical vapor deposition (CVD). Graphene was transferred from copper substrates to SiO­₂ wafers by a thermal release transfer tape. Copper was etched away from the tape-graphene combination by ferric chloride, and the tape was peeled away after heating, leaving graphene on the SiO₂ substrate. Contact angles were measured to …

Redesigning The Walker: A More Durable & Dignified Device, Gianna M. Curcio

Honors Capstone Projects - All

Aging and Rehabilitation Engineering is a prominent field with ample room for development of and improvement upon existing options. Surveying city sidewalks, family gatherings, hospital waiting rooms it becomes apparent that the need for mobility aids is abundant. My proposal for Capstone is to redesign the walker from both my mechanical engineering and sculptural perspectives. A walker is meant to improve the quality of life for those who are unable to walk unassisted, but should not come at the cost of the user’s dignity. The way we carry ourselves says a lot about us (i.e. character, will, and level of …

Numerical Analysis Of The Extrusion Of Fiber Optic And Photonic Crystal Fiber Preforms Near The Glass Transition Temperature, Mohamed Trabelssi

All Dissertations

Conventional clad core fiber optic technology has relied on a concentric structure of glass of different refraction indices. These conventional fibers suffer from constraints and limitations related to thermal expansion compatibility between the core and the glass. The new fiber technology broadly characterized as Microstructured Optic Fibers (MOFs) is intended to lift the limitations of conventional clad core fibers and also extend the range of application of fiber optics. Photonic Cristal Fibers(PCFs) are a special family of Microstructured Optic Fibers characterized by the presence of holes in the cross section of the fiber that are organized in a hexagonal pattern. …

Improved Wind Turbine Control Strategies For Maximizing Power Output And Minimizing Power Flicker, Quan Chen

Theses and Dissertations

For reducing the cost of energy (COE) for wind power, controls techniques are important for enhancing energy yield, reducing structural load and improving power quality. This thesis presents the control strategies studies for wind turbine both from the perspectives of both maximizing power output and reducing power flicker and structural load,

First, a self-optimizing robust control scheme is developed with the objective of maximizing the power output of a variable speed wind turbine with doubly-fed induction generator (DFIG) operated in Region 2. Wind power generation can be divided into two stages: conversion from aerodynamic power to rotor (mechanical) power and …

Retrofitting Two Solar Hot Water Systems For Year Round Operation, Zachary A. Cook

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Solar energy in a variety of applications is again becoming more widely used. Solar collectors have been installed during the construction of two Utah State University buildings: Wetlands Discovery located in Kaysville, Utah and Swaner Nature Preserve located in Park City, Utah. While these systems are capable of capturing a significant amount of solar energy, problems have been encountered when the demand is less than the system’s capacity. This project report documents the problems encountered while operating the two solar water heating systems and how the systems were modified to be operational year round under typical operating conditions. The peak …