Mechanical Engineering Commons^™

A Method For The Characterization And Selection Of Compliant Joints, Ronald George Saleeby

All Theses

A compliant joint is a connection between two bodies that derives its movement from the deflection of flexible members rather than rigid connections, like traditional joints. Compliant joints have potential advantages that include longer part life, reduction of parts in assemblies, and reduced wear. Traditional compliant mechanism design methodologies have limitations involving the burden of necessary knowledge required to satisfactorily use them. The method presented in this thesis was developed to provide compliant joint design solutions independent of the traditional methods of compliant joint design by allowing the selection of compliant joints from a repository. The repository is populated by …

Experimental Verification And Integration Of A Next Generation Smart Power Management System, Tavis Clemmer

Graduate Theses and Dissertations

With the increase in energy demand by the residential community in this country and the diminishing fossil fuel resources being used for electric energy production there is a need for a system to efficiently manage power within a residence. The Smart Green Power Node (SGPN) is a next generation energy management system that automates on-site energy production, storage, consumption, and grid usage to yield the most savings for both the utility and the consumer. Such a system automatically manages on-site distributed generation sources such as a PhotoVoltaic (PV) input and battery storage to curtail grid energy usage when the price …

Dynamic Response Of A Multi-Span Curved Beam From Moving Transverse Point Loads, Amanda Alexander

HIM 1990-2015

This thesis describes how to evaluate a first-order approximation of the vibration induced on a beam that is vertically curved and experiences a moving load of non-constant velocity. The curved beam is applicable in the example of a roller coaster. The present research in the field does not consider a curved beam nor can similar research be applied to such a beam. The complexity of the vibration of a curved beam lies primarily in the description of the variable magnitude of the moving load applied. Furthermore, this motion is also variable. This thesis will present how this beam will displace …

Understanding And Modeling Pathways To Thrombosis, John Seligson

HIM 1990-2015

This research will investigate techniques to create a sensor that is responsive to methane at 23°C. The approach will use the integration of a very thin film, which changes its resistive properties when methane gas is applied, deposited atop the surface of a piezoelectric substrate. An aluminum thin film interdigital transducer will launch a surface acoustic wave (SAW) that travels under the sensor’s gas-sensitive resistive thin film. The SAW/resistive film interaction changes the SAW amplitude, phase and delay. For this work, three films, tin dioxide (SnO2), zinc oxide (ZnO) and palladium (Pd) [1, 2] will be studied. Gas detection will …

Frequency-Domain Faraday Rotation Spectroscopy (Fd-Frs) For Functionalized Particle And Biomolecule Characterization, Richard Murdock

HIM 1990-2015

In this study, the magnetically-induced vibrations of functionalized magnetic particle suspensions were probed for the development of a novel optical spectroscopy technique. Through this work (1) the frequency-dependence of the faraday rotation in ferrofluids and (2) the extension of this system to elucidating particle size and conformation as an alternative immunossay to costly and labor/time intensive Western Blotting and ELISA has been shown. With its sensitivity and specificity, this method has proven to be a promising multi-functional tool in biosensing, diagnostic, and therapeutic nanomedicine efforts. Due to its ubiquitous nature in all optically-transparent materials, the farady rotation, or circular birefringence, …

A Mechanics-Based Approach For Putt Distance Optimization, Pascual Santiago-Martinez

HIM 1990-2015

Quantifying the core mechanics of putting is imperative to developing a reliable model that predicts post-collision ball behavior. A preliminary model for the stroking motion of putting and putter-ball collision is developed alongside experiments, establishing an empirical model that supports the theory. The goal of the present study is to develop a correlation between the backstroke of a putt, or the pre-impact translation of the putter, and the post-impact displacement of the golf ball. This correlation is subsequently utilized to generate an algorithm that predicts the two-dimensional ball trajectory based on putt displacement and putting surface texture by means of …

Design And Evaluation Of A Test Platform For Thermal Mechanical And Acoustical Loading, Abdi Jasmin

HIM 1990-2015

Next generation hypersonic cruise vehicle components will be subjected to a collection of loads not achievable in contemporary mechanical test platform. The purpose of this thesis is to demonstrate the design of a unique test platform for combined extreme environment (P-CEEn) needed to replicate thermal, acoustic and mechanical loading to be imparted on hypersonic fuselage panels. The panels are typically subjected to super-imposed cycling from hypersonic shock/impingement and aerodynamic pressure from the usual ascent-cruise-decent motion of the aircrafts combined with mechanical vibration at acoustic frequencies; moreover, these slender components will undergo conventional mechanical fatigue with compressive mean stress due to …

A Participatory Design Framework For Customisable Assistive Technology, Pearl O'Rourke

Doctoral

High product costs and device abandonment negatively affect people with disabilities who require Assistive Technology (AT), and poor product design is a root cause. The purpose of this research is to develop and demonstrate a participatory design framework for customisable AT, which addresses the need for low-cost assistive products that satisfy a broad range of consumers’ needs. This framework addresses two main gaps in the literature. First, user involvement in the design process of medical and rehabilitative products helps create products that are more effective but, although methods to involve users exist, there are currently scant techniques to translate the …

Comparison Of Evaluation, Measurement & Verification Processes: Arkansas To Bordering States, William Burgess Carlisle

Mechanical Engineering Undergraduate Honors Theses

The purpose of this paper is to compare Evaluation, Measurement, and Verification (EM&V) standards established by Arkansas and surrounding states. EM&V is the process to quantify the energy savings of an energy management project. This paper details the rules and regulation regarding the EM&V proceedings required by investor-owned utilities in providing energy-saving projects. By comparison of each state’s requirement, a clear understanding is found on where Arkansas stands in maturity of its program requirements. The reader will find Arkansas on the forefront of EM&V standardization that represents a model that surrounding states are striving to emulate.

Ligament Model Fidelity In Finite Element Analysis Of The Human Lumbar Spine, Mitchell Scott Hortin

Theses and Dissertations

The purpose of this project is to quantify the effects of increasing spinal ligament fidelity on the mechanics of the human lumbar spine using finite element analysis (FEA). In support of this goal, a material characterization study was completed to provide anisotropic, nonlinear material parameters for the human anterior longitudinal ligament. (ALL). Cadaveric samples of the human ALL were tested using a punch test technique. Multi- axial force-deformation data were gathered and fit to a commonly used transversely isotropic material model using an FEA system identification routine. The resulting material parameters produced a curve that correlated well with the experimental …

Globally Consistent Map Generation In Gps-Degraded Environments, Paul William Nyholm

Theses and Dissertations

Heavy reliance on GPS is preventing unmanned air systems (UAS) from being fully inte- grated for many of their numerous applications. In the absence of GPS, GPS-reliant UAS have difficulty estimating vehicle states resulting in vehicle failures. Additionally, naively using erro- neous measurements when GPS is available can result in significant state inaccuracies. We present a simultaneous localization and mapping (SLAM) solution to GPS-degraded navigation that al- lows vehicle state estimation and control independent of global information. Optionally, a global map can be constructed from odometry measurements and can be updated with GPS measurements while maintaining robustness against outliers.We detail …

Concurrent Engineering Through Parallelization Of The Design-Analysis Process, Eric Joseph Wardell

Theses and Dissertations

The disconnect between the way CAD and analysis applications handle model geometry has long been a hindrance to engineering design. Current industry practices often utilize outdated forms of geometry transfer between these different engineering software applications such as neutral file formats and direct translations. Not only to these current practices slow the engineering design process but they also hinder the integration of design and analysis programs.This thesis proposes a new, multi-user, integrated design-analysis architecture which allows auxiliary functions such as analysis and computer-aided manufacturing to be better connected with the computer-aided design. It is hypothesized that this new architecture will …

Modeling Of Environmentally Assisted Fatigue Crack Growth Behavior, Sree Phani Chandar Reddy

Dissertations

The formation of fatigue cracks and their propagation due to cyclic loading in metals have been a concern for more than hundred years. Since fatigue failure were first reported by the railroad industry in 1840s, tremendous progress has been achieved in understanding fatigue behavior of metals. But fatigue damage is still a concern due to its complex dependency on various environmental variable like humidity, temperature, time and corrosive environment. Although numerous theories and models have been proposed in the past, the effects of environment on fatigue crack growth (FCG) is not completely understood. This dissertation aims to shed light on …

Manipulating The Mass Distribution Of A Golf Putter, Paul J. Hessler Jr.

Senior Honors Projects

Putting may appear to be the easiest but is actually the most technically challenging part of the game of golf. The ideal putting stroke will remain parallel to its desired trajectory both in the reverse and forward direction when the putter head is within six inches of the ball. Deviation from this concept will cause a cut or sidespin on the ball that will affect the path the ball will travel.

Club design plays a large part in how well a player will be able to achieve a straight back and straight through club head path near impact; specifically the …

Examination Of Heat Flux Through A Surface Using Digital Image Processing Of Infrared Images, Nicholas D. True

Honors Theses

The task for this project was to design and construct a system that could be used to examine heat transfer through a surface by analyzing images produced using thermal imaging cameras. A long rectangular box made of pinewood was constructed and a light bulb was inserted to provide a heating element. The front face of the box was made to be interchangeable so that various materials could be tested. Two Flir I5 thermal imaging cameras were used to take pictures of both sides of the front face at specific time intervals in order to determine the temperature distribution of the …

Controller Area Network (Can) Bus J1939 Data Acquisition Methods And Parameter Accuracy Assessment Using Nebraska Tractor Test Laboratory Data, Samuel E. Marx

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Electronics have become a standard in agricultural equipment and the trend of “smarter” equipment is on the rise. To have “smarter” equipment, a working knowledge of the accuracy of the data being transmitted throughout that equipment is needed. The controller area network (CAN) bus is the current interface to machine operation data transmitted between electronic control units (ECUs).

Because CAN bus has been around for nearly thirty years, numerous devices have been created for interfacing with the bus. Choosing a device can be a challenge, especially without knowing if there are differences between the logging methods for true data representation. …

The Integration Of Heat Resources In A Solar Thermal-Heat Pump Hydronic System, John Degrove

Purdue Polytechnic Masters Theses

According to the U.S. Department of Energy, roughly 41% of the energy consumed in the U.S. is used the power buildings. Within that number, almost half is used to heat or cool the building. Current technologies allow for consistent thermal management, but most utilize energy harvested from fossil fuels or convert electricity back into thermal energy. Background literature shows that the utilization of alternative heat resources such as heat pumps and solar thermal collectors can greatly reduce the energy used for heat delivery while producing adequate heating performance. A combined hydronic system using a bank of solar thermal collectors in …

Aerodynamic Flow Field Characterization Of Airfoils With And Without Leading Edge Modifications, Oscar Hernandez

Theses and Dissertations - UTB/UTPA

Recently, much focus has been on comprehending the aerodynamic properties associated with the humpback whales pectoral fin. The perturbations found on its leading edge are believed to attribute to the humpbacks maneuverability significantly. These tubercles are assumed to be analogous to strakes on an aircraft, which generate large-scale vortices. More specifically, the vortices prompted by the leading edge increase the momentum exchange within the boundary layer, allowing the flow to remain attached at higher angles of attack, thus delaying stall and in turn increase lift by a passive means of reducing drag. The focus of this investigation is on characterizing …

An Automated Method For Hot-To-Cold Geometry Mapping, Brandon Levi Doolin

Theses and Dissertations

An Automated Method for Hot-to-Cold Geometry Mapping.

An Investigation Of Off-Design Operation In High Suction Performance Inducers, Ryan Collins Cluff

Theses and Dissertations

Three-dimensional two-phase unsteady CFD simulations were run on three and four-blade inducers for the purpose of analyzing differences in cavitation stability at design and off-design flow rates. At design flow rates, there were very small differences between the breakdown curves for the three and four-bladed inducers. However, at lower cavitation numbers, the three-bladed inducer exhibited up to three times the rotor forces than the four-bladed inducer. When moving to off-design flow rates, both inducers experienced multiple modes of cavitation instabilities including rotating cavitation, alternate-blade cavitation, and cavitation surge. The four-bladed inducer began experiencing the formation of these modes of instability …

Computational Modeling Of Alternating Current Potential Drop Measurement For Crack Detection Of Multi-Functional Ceramic Coated Structures, Simha Sandeep Rao

All Theses

Non-destructive testing and evaluation (NDT&E) is a set of techniques commonly used to evaluate a material for the presence of any flaws without actually degrading the material itself. The Alternating Current Potential Drop (ACPD) test method is one of the NDT surface methods used to determine the electrically insulating defects beneath the surface by injection of currents in the structure and measurement of the resulting voltage difference between two or more points on the surface. The presence of defects generally increases the resistance of the structure and hence causes the drop of measured voltage. The inversion of this data can …

Eight Degree Of Freedom Vehicle Model With Pitch, Yaw, Tire Control And Sensor Inputs, Sean T. Hirtle

Master's Theses

This research focuses on the development of an eight degree of freedom vehicle model in the MATLAB computing language. Its purpose is to provide flexibility in the modeling and implementation of signal inputs and crash avoidance logic while maintaining accuracy in the physics of the vehicle’s motion. Firstly, the equations of motion for the bodies involved under a reasonable set of assumptions were developed. Next the model was translated to computer code. By writing the model in SimuLink with *.m files, the modularity of the code is enhanced. To validate the model, several well defined tests were simulated.

To establish …

A Multi-Objective Optimization Method For Maximizing The Value Of System Evolvability Under Uncertainty, Jason Daniel Watson

Theses and Dissertations

System evolvability is vital to the longevity of large-scale complex engineered systems. The need for evolvability in complex systems is a result of their long service lives, rapid advances to their integrated technologies, unforeseen operating conditions, and emerging system requirements. In recent years, quantifiable metrics have been introduced for measuring the evolvability of complex systems based on the amount of excess capability in the system. These metrics have opened opportunities for optimization of systems with evolvability as an objective. However, there are several aspects of such an optimization that require further consideration. For example, there is a trade-off between the …

Burnout, No, And Flame Characterization From An Oxygen-Enriched Biomass Flame, Steven Andrew Owen

Theses and Dissertations

Concern for the environment and a need for more efficient energy generation have sparked a growing interest throughout the world in renewable fuels. In order to reduce emissions that negatively contribute to global warming, especially CO2, enormous efforts are being invested in technologies to reduce our impact on the environment. Biomass is an option that is considered CO2 friendly due to the consumption of CO2 upon growth. Co-firing biomass with coal offers economic advantages because of reduced capital costs as well as other positive impacts, such as NOx and SOx emission reductions. However, due to the large average particle size …

Active Control Of The Human Voice From A Sphere, Monty J. Anderson

Theses and Dissertations

This work investigates the application of active noise control (ANC) to speech. ANC has had success reducing tonal noise. In this work, that success was extended to noise that is not completely tonal but has some tonal elements such as speech. Limitations such as causality were established on the active control of human speech. An optimal configuration for control actuators was developed for a sphere using a genetic algorithm. The optimal error sensor location was found from exploring the nulls associated with the magnitude of the radiated pressure with reference to the primary pressure field. Both numerically predicted and experimentally …

Design And Manufacturing Of A Mecanum Wheel For The Magnetic Climbing Robot, Shruti Deepak Kamdar

Doctoral Dissertations and Master's Theses

An AndyMark Mecanum Wheel has been re-designed for better performance and utilization by Helical Robotics. Mecanum Wheel is a complex "Omni-Directional" wheel that currently contains several drawbacks. The drawbacks include design, usage of hobby grade material, bumps in rollers, etc. A comprehensive design of the Mecanum wheel is being presented using Computer Aid Software, CAD and analysis tools, such as Finite Element Analysis, FEA. The different concepts were hand sketched using various parameters and then implemented in a CAD software-- CATIA. The Mecanum Wheel's feasibility was thoroughly studied through ANSYS software. Load analysis was performed using various materials and several …

Experimental And Analytical Study Of An Open Cathode Polymer Electrolyte Membrane Fuel Cell., Alex Martin Bates

Electronic Theses and Dissertations

In this thesis four different fuel cell designs were simulated with consideration for electrochemical effects, reactant species transport, and heat transfer. Simulation results include the mass fraction of hydrogen, oxygen, and water, temperature gradient, pressure gradient, and velocity profile. One of the fuel cell designs was experimentally tested using two different membrane electrolyte assemblies; one high performance and the other high durability. The polarization curve resulting from simulation compares well with the polarization curve produced by experimental work. A 16 cell fuel cell stack was simulated with consideration for stack compression. The same fuel cell stack was tested experimentally for …

Surface Characterization Of 316l Stainless Steel For Biomedical Applications, Lawrence Cano

Theses and Dissertations - UTB/UTPA

Stainless steel alloys play an important role in the field of biomaterials due to their exceptional corrosion resistance and biocompatibility. These alloys have the capability to enhance the quality of a human life by altering various structures of human physiology. The close proximity these alloys have with destructive body fluids, ion dissolution is a detrimental cause from the corrosion initiative and may cause unfavorable reactions. A view on developing an improved compatible surface for the human body leads to implementation of different chemical surface modifications used for creating features that must be corrosion resistant and biologically active without changing the …

Available Work Rate Of A Reversible System Bounded By Constant Thermal Resistances Linked To Isothermal Reservoirs, Jim Mcgovern

Conference Papers

Exergy analysis is based on the concept of an idealized, all-enclosing reference environment that has infinite heat capacity and thermal conductivity, and is in equilibrium. The actual surroundings of a real plant such as a heat engine, a heat pump or a refrigerator may differ significantly from the ideal. First law performance parameters and second law rational efficiency are examined. The concepts of finite time thermodynamics are applied in an attempt to refine the concept of T0, the environmental reference temperature, thereby making exergy analysis more reflective of reality.

Systems Modeling And Economic Analysis Of Photovoltaic (Pv) Powered Water Pumping Brackish Water Desalination For Agriculture, Michael A. Jones

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The objective of this study was to determine the economic viability of solar powered water pumping and desalination systems for agriculture. Growing global demand for agricultural production has put increased pressure on limited freshwater resources in various locations around the word. Many areas have low quality groundwater resources that have not been utilized for agriculture due to limited availability to electricity, high operational costs of diesel generators and the economics associated with water pumping and processing. Reverse osmosis is a desalination technology that removes salts and other minerals from low-quality water, making it fit for drinking or irrigation. Reduced costs …