Mechanical Engineering Commons^™

Evolutionary Algorithms For Function Model Synthesis, Amaninder Singh Gill

Theses and Dissertations

Function modelling plays an essential role in the systematic design process. Designers are trained in the academia trained on function models, yet the acceptance of function models in the industry remains sparse. A possible reason is that there is a lack of computational support for synthesizing function models. The research presented in this dissertation aims to fill that gap. A conceptual proof of function model synthesis using a Genetic Algorithm (GA) is initially presented. Thereafter a priori rules to evaluate function model have been developed. These rules do not rely on a designer conveying designer intent to the algorithm, which …

Thermoelectric-Based Cooling Systems For Building Application: A Sustainable Solution, Seyedehmohadeseh Seyednezhad

Theses and Dissertations

In the United States, buildings account for a large share of the annual energy consumption, nearly 40%. Fossil fuels including coal, oil, and natural gas account for the main source of electric power generation and constitute the largest portion of the building energy consumption. Such a high level of fossil fuel consumption is a multifaceted challenge as demand for energy grows, and natural resources become scarce and expensive, while the climatic effects of massive energy use will be clearly felt by all. As a necessary component for occupants’ thermal comfort, cooling and air conditioning systems are among the largest energy …

Developing A Prototype Energy Harvesting Device For Powering Wireless Onboard Condition Monitoring Sensor Modules For Railway Service, Martin Amaro Jr.

Theses and Dissertations

An energy harvesting system is being developed to power a wireless bearing health monitoring device. In contrast to other monitoring systems, this wireless monitoring device is a low-powered onboard solution. Powered by a 3.7-Volt lithium-ion battery, the device can continuously function for several months on a single charge. By implementing an energy harvesting system, the life of the battery can be increased reducing the overall maintenance, electronic waste, and time needed to replace the batteries. The harvesting system uses thermoelectric generators to convert the heat generated in the bearings into electricity. The system is composed of aluminum heat sinks, a …

Synthesis And Characterization Of Copper Oxide Nanofibers, Shishir Barai

Theses and Dissertations

The aim of this study was to develop polymer-derived Copper (II) Oxide (CuO) nanofibers through centrifugal spinning technique and subsequent calcining. To obtain the force spun pre-ceramic copper acetate nanofibers, 15% wt, 25% wt, 35% wt, 50% wt% copper acetate (active material) and poly (vinyl) alcohol ( PVA) solutions was prepared with deionized water (DI) as solvent and spun at 7500 rpm in a FibeRio Cyclone. Thermogravimetric analysis (TGA) was implemented to determine the thermal degradation behavior of the pre-ceramic nanofibers. These nanofibers were then calcined at three different temperatures (500, 600 and 700°C) to produce CuO nanofibers. The microstructure, …

Lubrication Performance Of Vegetable Oils Modified With Halloysite Clay Nanotubes (Hnt) As Lubricant Additives, Md Abu Sayeed Biswas

Theses and Dissertations

Vegetable oil-based nano-lubricants are a great alternative to petroleum-based lubricants because of their less adverse impact on the environment. This work evaluates the tribological performance of sunflower, corn, and peanut oils modified with halloysite clay nanotubes (Al2Si2O2(OH)2nH2O) as lubricant additives at different concentrations. To analyze the tribological performance of the nano-lubricants, a block-on-ring tribometer was used following the ASTM G-077-17 standard procedure. Characterization of HNT was carried out by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Thermogravimetric Analysis (TGA). The effect of the HNT on the lubrication performance of the newly developed vegetable oil-based nano-lubricants was evaluated, and the …

Assessing The Effectiveness And Efficacy Of Wireless Onboard Condition Monitoring Modules In Identifying Defects In Railroad Rolling Stock, Lee R. Cantu

Theses and Dissertations

Many industries have begun shifting into the Internet of Things (IoT) in the 21st century. To help ease this transition for the rail industry, The University Transportation Center for Railway Safety (UTCRS) has partnered with Hum Industrial Technology, Inc. (HUM) to help complete the development of a Wireless Onboard Condition Monitoring system named the ‘Boomerang™’. This product allows customers to schedule proactive maintenance on their railcars to replace defective wheels and/or bearings, saving them time, money and potentially preventing costly catastrophic derailments. The UTCRS research team has established thresholds to determine defective bearings utilizing thermal and mechanical sensors.

The effectiveness …

Molecular Dynamics Study Of Atomic Diffusion In Cantor High Entropy Alloy In The Selective Laser Melting Process, Mathew Z. Farias

Theses and Dissertations

High entropy alloys (HEAs) are compositionally complex alloys that are comprised of 5 or more principle elements at near equimolar concentrations. The Selective Laser Melting (SLM) method generally melts pure elemental powders or prefabricated alloy powders, this process allows for the production of heterogeneous structures that would be difficult to create through more conventional means. In-situ alloying in SLM, or Laser Additive Alloying (LAA), using pure elemental powders is a promising means of producing what would otherwise be costly and difficult to fabricate products with less defects using prefabricated powders, therefore this new approach could enable the ability to …

Synthesis And Characterization Of Centrifugally Spun Molybdenum-Based Nanomaterials For Lithium-Ion Batteries, Ramiro Gonzalez Jr.

Theses and Dissertations

The work presented in this thesis focuses on the processing and development of transition metal compound composite fibers as anode materials for rechargeable lithium-ion batteries (LIBs). Among the transition metal compounds, molybdenum compounds have risen as promising candidates of advanced electrode materials, in view of their natural abundance, virtuous mechanical/thermal stability, rich chemistry, high theoretical specific capacity, and multiple oxidation states of Mo. The current work reports synthesize MoO2/C and MoO3/C composite fibers drawn from centrifugal spun ammonium molybdate/PAN precursor fibers, followed by a thermal treatment stabilizing in air and calcination under argon atmosphere. The weight ratios of (MoOx, 2 …

Development Of A Compact Core Flooding Apparatus For Matrix Acidizing Applications, Antonio Hernandez Zuniga

Theses and Dissertations

Matrix Acidizing is defined as a well stimulation technique in which the acid is injected into the formation with the purpose of dissolving the minerals present and thus enhancing the permeability of the formation and facilitating the extraction of oil and/or gas from the formation. The primary goal of acid diversion is the creation of wormholes and ramification paths that allow the fluid to flow from the higher to the lower permeability zones of the limestones, sandstones or carbonate reservoirs. Naturally, as the injected acid will follow vugs, fractures and pores, HCl is used because of its quick reaction and …

Selective Laser Melting Of Titanium Diboride: A Study Of The Energy Density Effects, Lazaro Lopez Mendez

Theses and Dissertations

Natural titanium diboride (TiB2) has been reported the 5th hardest material on earth. Due to its superior properties, such as high density, high elastic modulus, and high compressive strength, TiB2 becomes one of the most suitable ceramic reinforcements for applications with severe friction and heavy loading conditions. This study is intended to produce TiB2 using 3D additive manufacture (AM) technology, and then to understand the tribological property of the AM fabricated TiB2 specimens. In this study, a laser additive alloying (LAA) process was developed based on a Renishaw AM laser system. One mm thick samples were prepared using the LAA …

Development Of Vegetable Oil-Based Nano-Lubricants Using Montmorillonite Clay (Mmt) Nanoparticles As Lubricant Additives, Md Mashfiqur Rahman

Theses and Dissertations

Because of the environmental impact and price volatility, there has been a growing concern on the use of petroleum-based lubricants. This issue has stimulated research into the development of biodegradable lubricants like vegetable oils. In this study, the tribological and rheological behavior of sunflower, peanut, and corn oils modified with Montmorillonite nanoclay (MMT) as lubricant additives were evaluated at various concentrations. A custom-made block on ring tribotester was used to evaluate the wear and friction characteristics of the nano-lubricants, following the ASTM G-077-05 standard. The effects of concentration and shear rate on shear viscosity were studied using a parallel plate …

High Performance Electromagnetic Interference Shielding From Lightweight-Flexible Polymer Composite Fiber Structures, Fariha Rubaiya

Theses and Dissertations

This study focuses on the development and characterization of fiber-based polymer composite structures with the goal of developing high performance, flexible, lightweight, and cost-effective materials for electromagnetic interference shielding and piezoelectricity. Polyvinylidene fluoride (PVDF) was used as the base fiber mat while polyaniline (PANI), polypyrrole (PPY), polyindole (PIN), polydiacetylene (PDA) and Zn2GeO4 (ZGO) were incorporated via solution mixing and in-situ polymerization. The PVDF fine fiber systems were produced using the Forcespinning® method. Morphology, structure, thermal stability, electrical properties, EMI shielding effectiveness and piezoelectric performance of the fiber mats were analyzed. The composite system containing 1.25 wt. % of ZGO-PVDF displayed …

Charged Particle Environment Testing Of A Deep Space Radiation Shield With Associated Fabrication And Calibration Of Pulsed Power Systems, Mark Bedford Moffett

Theses and Dissertations

Space radiation is one of the primary dangers faced outside of the protective magnetosphere of Earth. Despite the persistent radiation threat to self-contained human habitation and the risk of increased exposure during long-duration missions, reliable long-term radiation protection is not well-developed. Active shielding is an avenue of preventative radiation protection that could be deployed to protect astronauts and biological life from the effects of radiation. This dissertation explores the design scalability of an active magnetic shield for protecting against isotropic radiation in deep space. Each shield is composed of two concentric, elliptical layers of circular conducting coils, each arranged like …

A Comparative Study On The Application Of Intelligent Algorithms As The Solution Of Inverse Heat Conduction Problems, Dominic Allard

Theses and Dissertations

A critical component necessary for the safety and survival of space vehicles are the thermal protection systems (TPS). Especially when subject to atmospheric re-entry, the heating loads subject to the space vehicle requires the implementation of extensive protection. The TPS commonly used currently are passive ablative materials which burn away under extreme heat flux. Due to the nature of the material and the incident heat flux, it is not feasible to attain accurate, real-time measurements for the boundary conditions with sensors placed on the surface of the space vehicle. The ability to do such would allow opportunities to implement active …

Application Of Ensemble Methods For Solving Offshore Wind Farm Layout Optimization Problems, Puyi Yang

Theses and Dissertations

Wind energy is considered as one of the most promising renewable energy sources. The intent of this dissertation is to assess the application of ensemble methods on offshore wind farm layout optimization. In this regard, four research questions are considered and addressed accordingly each of which are discussed in detail in a separate chapter (chapter 2 to 5). The first research question is focused on choosing appropriate analytical wake model to be used for the wind farm layout optimization (WFLO) problems in this dissertation. The WFLO problem is a complex and non-convex optimization problem. The accuracy of analytical wake models …

Coupling A Parametric Wave Model Into Hydrodynamic Ocean Circulation Forecasts To Improve Efficiency Of Nested Estuarine Storm Surge Predictions, Caleb Tye Lodge

Theses and Dissertations

Efficiency in storm surge modeling is crucial for forecasting coastal hazards in real-time. While computation cost is trivial to organizations with ample resources, the robustness of forecasts generated by most parties are restricted by wall-clock time. The Parametric Wave Model (PARAM) was developed by Boyd and Weaver (2021) as an alternative to computationally expensive wind-wave models when modeling estuarine environments. For this study, PARAM has been tightly coupled with the ADCIRC hydrodynamic model to become ADCparam, then integrated into the Multistage ensemble forecast system, a one-way nesting framework for modeling waves and circulation in coastal estuaries developed by Taeb and …

Dynamic Modeling Of A Three Degree Of Freedom Reaction Sphere, Joshua Michael Byron

Theses and Dissertations

This thesis presents a method to simulate the dynamics of a three degree of freedom, electromagnetically suspended Northrop Grumman Corporation Reaction Sphere (NGCRS) in MATLAB Simulink® by computing the magnetic force and torque relations offline, using COMSOL® Multiphysics. The goal of the thesis is firstly to demonstrate through Finite Element Magnetic Modeling (FEM) that magnetic field interactions between a stator levitation electromagnet (EM) and the rotor permanent magnets (PM) are limited to a single EM-PM pair and that all other PMs can be considered decoupled from the EM. Secondly, this thesis aims to demonstrate that a set of generalized magnetic …

An Evolutionary Inspired Framework For Grasp Planning Automation On Sheet-Metal Parts With Multi-Type Grippers, Jicmat Andres Ali Tribaldos

Theses and Dissertations

Industrial robot-mounted grippers are commonly used in the automotive industry to position, manipulate, and immobilize sheet-metal parts during several manufacturing and assembly operations. Nowadays, the use of grippers that use two or more different gripping principles such as magnets, suction cups, and fingers to accomplish the gripping task is common. Automation of the steps involved in the design of these multi-type grippers is essential to the timely introduction of new vehicles to the market. The main reason being that production of the vehicles cannot start before designing, testing, and building the grippers for its components, but the design of the …

A Machine Learning-Based Approach To Predict And Optimize The Performance Of Zero Energy Building (Zeb): A Case Study For Florida, Benjamin Kubwimana

Theses and Dissertations

Machine learning is currently one of the most searched fields aiming to solve real-life problems. Building simulation software tools help engineers estimate building energy behaviors before the actual construction, allowing implementation of more energy efficient choices in building design and construction. Current building energy simulation software tools are mostly physics-based and still lack the benefit obtained with machine learningbased modeling, which offers fast and less computationally expensive techniques to build energy models and efficiently perform design optimization. This thesis presents a machine learning-based approach for building energy modeling and optimizing design parameters to minimize building’s energy consumption. The study is …

Additive Manufacturing Of Cork, A Cold Spray Technology, Kimberly Kay Dickey

Theses and Dissertations

Cold Spray Additive Manufacturing is a technology capable of mass manufacturing components with complicated geometry and coating substrates in hard-to-reach areas. In addition, cold spray also has the ability of conducting a green manufacturing process, with zero waste of renewable feed material, and zero gas and chemical emission. This paper investigates solely cold spray as an additive manufacturing technology with cork as the natural material. CFD results were used to predict the physical behavior of air and the cork particles. After unsuccessful coatings, final results showed that when moisture is added, cork is successfully cold sprayed, and agglomeration is experienced. …

System Identification Of Postural Tremor In Wrist Flexion-Extension And Radial-Ulnar Deviation, Sydney Bryanna Ward

Theses and Dissertations

Generic simulations of tremor propagation through the upper limb have been achieved using a previously developed postural tremor model, but this model had not yet been compared with experimental data or utilized for subject-specific studies. This work addressed these two issues, which are important for optimizing peripheral tremor suppression techniques. For tractability, we focused on a subsystem of the upper limb: the isolated wrist, including the four prime wrist muscles (extensor carpi ulnaris, flexor carpi ulnaris, extensor carpi radialis, and flexor carpi radialis) and the two degrees of freedom of the wrist (flexion-extension and radial-ulnar deviation). Muscle excitation and joint …

Development Of Acoustic Metamaterial Noise Barriers And Simultaneously Harvesting Energy Using Smart Materials, Fariha Mir

Theses and Dissertations

In our surroundings abundant energy, we either feel through component vibration or hear noises from acoustic sources. Harvesting these unused and untapped green energy in the form of ambient vibration, and acoustic sounds is an emerging field of research in recent years. Utilization of the energy within a wide band of the frequency spectrum originated from the vibrational sources alone stands as one of the most promising ways to power small electronic devices, smartphones, local structural health monitoring sensors, home, and workshop appliances. These abundant sources of green energy are available in almost all the engineering industries, workshops, manufacturing facilities, …

Effect Of Crystal Size On The Failure Mechanics Of Polymer Bonded Explosives, Chizoba Onwuka

Theses and Dissertations

Polymer bonded explosives (PBXs), typically constitute 80-95% of energetic crystals and 5-20% of a soft polymer binder, are widely used in extreme loading conditions such as rocket propellants and explosive munitions because of their high performance and low sensitivity. The particle size of crystals has a significant effect on the mechanical properties of most polymer particulate composites.

In the study, the effect of particle size on the deformation behavior of PBX under dynamic loading is investigated. The study involves testing polymer bonded sugar (PBS) samples, a well-known mechanical simulant of PBXs, with four different crystal sizes: coarse, intermediate, fine and …

Purification Of Uranium Tetrafluoride Using Ammonium Bifluoride, Kyle Robert Foster

Theses and Dissertations

Molten salt reactors are being deployed as one of the Generation IV nuclear reactor concepts starting in 2025. While their applications and safety potential are considered extremely advantageous, there is a lack of operating history to draw on, so thorough understanding of proposed molten salt materials’ thermochemical behavior is crucial to their successful implementation.

The most prominent fissile fuel proposed for molten salts is uranium tetrafluoride (UF4) using ²³³U of the thorium fuel cycle. UF₄ is extremely hygroscopic, meaning it will react with moisture and oxygen in its environment, so as-received powders contain significant levels of impurity. In …

Implementation Of Stereo Digital Image Correlation For In-Plane Strain Measurements To Quantify The Anisotropic Behavior, Plastic Flow, And Strain Hardening Of Extruded Aluminum Alloy, Farzana Yasmeen

Theses and Dissertations

The efficient use of metals is important in various industries, including aerospace, automotive, and energy systems. In each case, the type and range of combined loading conditions can be quite different. The approaches to stress analysis of such complex engineering components and assemblies often are limited to elastic conditions. For those cases where components are relatively thin, elastic-plastic conditions are present; there is continuing interest in assessing the accuracy of analytic and computational models for combined loading conditions. In such cases, experiments performed with axial and shear loads (e.g., tension-torsion) provide baseline data regarding the relationship between applied stresses and …

Application Of Digital Transformation In The Water Desalination Industry To Develop Smart Desalination Plants, Ibrahim Yousif

Theses and Dissertations

Fresh water shortage threatens the development and prosperity of many countries including several areas in the United States. Sea and ground water reverse osmosis desalination is rapidly becoming a dominant technology for overcoming water shortage threats by providing cost-effective freshwater production. Digital transformation can be used to help facilitate and advance water treatment technologies by reducing costs and minimizing downtime. Digital transformation is a process that encapsulates digital tools and technologies such as cloud computing, machine learning, artificial intelligence, the internet of things, and virtual/augmented reality. It is a process where objects in the physical world are given virtual replicas …

Mechanical Strength Of Sic Composite Tubing Under Uniaxial And Multiaxial Loading, Colton Corley

Theses and Dissertations

Silicon carbide fiber reinforced silicon carbide matrix composite is one of the candidate materials for accident tolerant nuclear fuel cladding concepts. In a Nuclear power plant, the reactions between the fuel, cladding, and coolant in a potential loss of coolant accident(LOCA) are of utmost importance to ensure safety in the accident tolerance of such plants. It is for this reason that SiC(silicon carbide) composite tubes have been selected as a possible alternative to the older Zirconium based cladding methods currently used in the industry, which were a partial cause of the Fukushima 2011 meltdown. To serve as fuel cladding, a …

Development Of A Rapid Compression And Expansion Machine To Characterize The Ignition Propensity Of Multi-Component Liquid Fuels, Jonathan Joseph Morreale

Theses and Dissertations

Combustion has been the primary source for energy production, whether it be from coal, oil, or natural gas, for a very long time. With increasing population and therefore an increased demand for energy, efficiency is becoming a concern. In order to increase efficiency, engines have been downsized and compression ratios have been increased. In doing so, problems have arisen such as knock and low speed pre-ignition. To better understand these problems, an investigation into how fuels ignite at higher pressures is necessary. Real fuels are comprised of multiple components that exhibit significant variations in their own physical and chemical characteristics. …

Searching Extreme Mechanical Properties Using Active Machine Learning And Density Functional Theory, Joshua Ojih

Theses and Dissertations

Materials with extreme mechanical properties leads to future technological advancements. However, discovery of these materials is non-trivial. The use of machine learning (ML) techniques and density functional theory (DFT) calculation for structure properties prediction has helped to the discovery of novel materials over the past decade. ML techniques are highly efficient, but less accurate and density functional theory (DFT) calculation is highly accurate, but less efficient. We proposed a technique to combine ML methods and DFT calculations in discovering new materials with desired properties. This combination improves the search for materials because it combines the efficiency of ML and the …

An Investigation Of The Ignition Propensities Of Fuels Perturbed By Nitrogen Monoxide, Ackmer Robinson Iii

Theses and Dissertations

Quantitative structure property relationship (QSPR) regression models were developed based on the chemical functional group distribution of toluene reference fuels (TRF, mixtures of n-heptane, iso-octane, and toluene) for RON, MON, and DCN. The QSPR regression models were developed using DCN measurements from this study as well as RON/MON data available in literature. The correlations between RON/MON and DCN were analyzed. The ignition propensity of TRFs perturbed by NO addition was also investigated in this study. The interactions between the chemical functional groups and NO were investigated using an ignition quality tester (IQT). It was found that the increase in the …