Mechanical Engineering Commons^™

Mathematical Modeling Of A Two Wheeled Robotic Base, Kathryn Remell

Mechanical Engineering Undergraduate Honors Theses

This thesis presents the concept of using a two wheeled robot on the moon and briefly explores the requirements for successful long term operation in a lunar environment. The mathematical model for the motion of a robot with two fixed wheels on a differential drive with in a global reference frame. The robot is assumed to be balancing a platform so the mathematical model to balance the platform with wheel motors is also developed and briefly evaluated.

Characterizing High Entropy Alloys For Hypersonic Applications, Katherine Pettus

Mechanical Engineering Undergraduate Honors Theses

In this paper, the properties of a new and broad class of materials, high entropy alloys (HEAs), were investigated and evaluated for hypersonic applications. The plan was to identify candidate hypersonic HEAs and model the high-temperature strength using new advanced material models that account for asymmetry and anisotropy characterized with available test data. After accessing a local database of HEAs and their material properties in collaboration with Dr. Gorsse et al., it was realized the knowledge of HEAs is currently very broad but lacks depth. While hundreds of HEAs have been created and tested, none so far have both sufficient …

Improving The Performance Of An Ead Aircraft By Use Of A Retractable Electrode System, Michael Alexander Fredricks

Mechanical Engineering Undergraduate Honors Theses

Electroaerodynamic (EAD) propulsion is a growing area of research for small, low powered aircraft. Recent tests of EAD aircraft have demonstrated low performance in unpowered, gliding flight. The purpose of this paper is to investigate the effect of a retractable electrode system on the flight performance of an EAD aircraft. An analysis of electrode drag contribution on the MIT ionic wind plane’s performance predicts a maximum lift to drag ratio of 22, with the addition of a retractable electrode system, for a similarly sized and modeled EAD aircraft. An experiment is developed using a prototype aircraft, launcher, and retraction system …

Development Of A Computational Framework For Estimating Knee Joint Contact Forces In Running, Sean W. Kapp

Honors Theses

The prevalence of running as a form of exercise and the necessity of walking for simple locomotion obscure massive forces and moments within the body. An especial area of concern is the knee, as common among these injuries is knee pain as a result from high impact on the ground or ground reaction forces. These forces are altered by the foot strike pattern of the individual; in this study, either rearfoot strike (RFS) or forefoot strike (FFS). This alteration will impact internal forces conducted upward through the body. Given the complexity of the motion of running and the forces involved, …

Development Of A Software For The Optimization Of Mechanical Structural Elements, Joshua Gross

Honors Capstone Projects

The goal of this software is to develop the framework for the optimal design of a mechanical structural element that minimizes the total part volume while maintaining the induced stress below an acceptable level. The software starts with input from the user, which is a set of ANSYS APDL commands that include constant dimensions, applied force, and initial values for the variable dimensions. Then, a MATLAB script modifies the variable dimensions, and the output is analyzed by the nonlinear programming solver known as Sequential Gradient-Restoration Algorithm. Finally, the solver converges on the dimensions that produce a structurally viable element with …

Secondary Resonances Of Electrostatically Actuated Mems And Nems Circular Plates, Julio S. Beatriz

Theses and Dissertations

Two methods are used in the investigation, which are the Method of Multiple Scales (MMS) and the Reduced order Model (ROM) with up to 6 modes of vibration. The MMS is done in three ways, one based on soft excitation and the other models based on the usage of the bookkeeping parameter, ε, in the electrostatic term. These are referred to as the 1 term no ε, and the 2 term no ε, which allow it to model hard excitation. The influence of the number of terms in the Taylor expansion is explored.

These methods are used to investigate the …

Novel Coating Methods On Centrifugally-Spun Polymer Fibers For Applications In Lithium-Ion Batteries, Jonathan G. Ayala

Theses and Dissertations

The work presented in this thesis focuses on the processing, characterization, and electrochemical results of centrifugally spun composite carbon fiber electrodes for application as anode material in lithium-ion batteries. The work is presented as a compilation of two major projects. First, the use of novel Co3O4 wet coatings to increase the capacity of carbon fibers produced from Polyacrylonitrile (PAN). In this work, PAN fibers are produced via the Forcespinning method, and were heat treated by oxidation in air at 200 °C for four hours, and subsequent carbonization at 600 °C for six hours. The electrochemical performance of the Co3O4/C composite-fiber …

Standardizing Patient Generated Sleep And Step Data For Evidation Health, Jade Desmet, Monroe Erle, Jamie Cullen

Industrial and Manufacturing Engineering

Since medical data has gone digital there has been a lack of standardization among wearable devices for managing the data. Evidation Health is a company that collects biometric data from a wide variety of wearable devices through their app, Achievement. Evidation is built upon a foundation of user privacy and control over permissioned health data. This project is in partnership with them, focusing on creating a standard data model and ETL tool for sleep and step data across the wearable devices Fitbit, Apple Watch, and Oura Ring. There is not yet a successful standardization for this health data, and the …

Design For Metal Fused Filament Fabrication (Dfmf3) Of Ti-6al-4v Alloy., Mohammad Qasim Shaikh

Electronic Theses and Dissertations

Additive manufacturing (AM) offers unmatchable freedom of design with the ability to manufacture parts from a wide range of materials. The technology of producing three-dimensional parts by adding material layer-by-layer has become relevant in several areas for numerous industries not only for building visual and functional prototypes but also for small and medium series production. Among others, while metal AM technologies have been established as production method, their adoption has been limited by expensive equipment, anisotropy in part properties and safety concerns related to working with loose reactive metal powder. To address this challenge, the dissertation aims at developing the …

Simulation Of Fracture Strength Improvements Of A Human Proximal Femur Using Finite Element Analysis., Waleed Ebraheem Alim

Electronic Theses and Dissertations

The most common hip fracture in the elderly occurs as a result of a fall to the side with impact over the greater trochanter resulting in a fracture of the proximal femur. The fracture usually involves the femoral neck or the intertrochanteric region. It has recently been determined that the fracture crack of a hip fracture typically initiates on the superior-lateral cortex of the femoral neck and then propagates across the femoral neck, resulting in a complete fracture. The strength of the superior-lateral cortex of the femoral neck is likely determined by the combined properties of the generally thin cortex …

Design Of An Ice-Class Propeller For The Mv Yahtse, An Icebreaking, Car And Cargo, Roro Ferry, Mara Kramer

Senior Honors Theses

During early-stage ship design, a propulsion system must be matched with data from a resistance and propulsion analysis to determine the propulsion power required for the vessel to run at its design speed. Typically, this process is completed within NavCAD; however, NavCAD does not have a method to calculate icebreaking resistance or design a propeller to meet the ice-class criteria stipulated by the International Association of Classification Societies (IACS). This paper displays and discusses Python scripts written to complete the resistance and propulsion analysis, propeller optimization, and propeller structural design meeting IACS criteria for an icebreaking, RoRo car and cargo …

Transient Performance And Melt Front Characterization Of Phase Change Materials, Tyler Stamps

Mechanical Engineering Undergraduate Honors Theses

Thermal management systems are often over-designed for average use in order to handle spikes in heat generation, which increases the spatial and financial requirements. One way to mitigate this is via the use of phase change materials (PCMs) as thermal buffers and storage media. This material type exhibits excellent latent heat at the sacrifice of conductivity. The present paper examines the melt front behavior of a common solid to liquid PCM, paraffin, experimentally and numerically. The experimental scenario was a block of PCM with a constant temperature heat flux introduced on one end and a constant temperature cold boundary condition …

Nanoscratch Study Of Diamond-Like Carbon Coatings With A Polydopamine + Sio2 Adhesive Underlayer, Anna Fisher

Mechanical Engineering Undergraduate Honors Theses

Diamond-like carbon (DLC) coatings have a wide array of desirable characteristics such as low friction, high hardness, and scratch resistance. Due to high residual stress and thermal mismatch, DLC films experience adhesion difficulties when bonded with metallic substrates, leading to cracking and delamination. In this study, the properties of a new coating with a polydopamine underlayer and silica nanoparticles bonded to a stainless-steel substrate (PDA+SiO2/DLC) were studied alongside three other samples, one with a polydopamine underlayer (PDA/DLC), one with a trimethylsilane (TMS) underlayer (TMS/DLC), and one with no underlayer (DLC only). Nanoscratch tests were performed with a 1 μm spheroconical …

Noise Control In Sorting Conveyors, Eyra Herrera

Mechanical Engineering Undergraduate Honors Theses

E-commerce has increased the necessity of effective material handling equipment in warehouses and distribution centers. Sorter conveyors systems facilitate material handling by providing a reliable and automated system to classify and distribute products in a gentle and rapid manner. With the steady increase of speed in sorter conveyors to satisfy today’s industry demand, some systems have started to produce high noise levels that could potentially affect workers’ health. Since decreasing the speed of these conveyors is not a viable option to decrease noise in sorter equipment, industries have opted to find other ways to apply noise control to their equipment. …

Algorithm Development Of Topology Optimization For Pcm Based Heat Sinks, Diego L. De Los Reyes

Mechanical Engineering Undergraduate Honors Theses

With the inherent usage of the computer when dealing with additive manufacturing, it only makes sense to use that higher computing power through simulation and iterative design to use the mathematical concept of topology and optimize the kind of geometry and shapes to be produced for a certain application, especially thermal ones since most 3D printing applications focus on purely the mechanical. To determine what the shape will be, an objective function of how much heat can be dispersed from a hypothetical heat source, assumed to be a type of electronic device, is maximized while being constrained by other variables, …

Thermal Testing And Characterization Of Nanoparticles Synthesized For Biological Treatment, Tonie Butler

Mechanical Engineering Undergraduate Honors Theses

The overall goal of this research project is to synthesize iron core, silica capped nanoparticles that, when they are exposed to a particular magnetic field, will react by increasing in temperature and emitting substantial thermal output. They will be injected into the human body for biological benefit by targeted thermal radiation. Once in the human body, ideally, they will be able to target a specific area, and then a magnetic field will be applied to induce thermal output through the process of hyperthermia. As the nanoparticles emit heat, they will mimic the natural bodily behavior seen by way of hyperthermia, …

Design And Control Of A Peristaltic Pump To Simulate Left Atrial Pressure In A Conductive Silicone Model, Jeremy Collins

Mechanical Engineering Undergraduate Honors Theses

According to the CDC, atrial fibrillation is responsible for more than 454,000 hospitalizations and approximately 158,000 deaths per year. A common treatment for atrial fibrillation is catheter ablation, a process in which a long flexible tube is guided through the femoral artery and to the source of arrhythmia in the heart, where it measures the electrical potential at various locations and converts problematic heart tissue to scar tissue via ablation. This paper details the design and control of a low-cost ($400) peristaltic pump system using repetitive control to replicate blood pressure in the left atrium in a conductive silicone model …

Multiscale And Multimaterial 3d Printing: Impact Of Feedstock Properties And Processing Parameters On Printed Parts, Kazi Md Masum Billah

Open Access Theses & Dissertations

Material extrusion additive manufacturing (AM) technology is one of the most commonly used technology to fabricate functional prototypes and end-use application parts with custom design. The evolution of the extrusion technology led this particular AM process to grow in many aspects such as new materials development, new design thinking, fabrication of parts in multiscale length, and manufacturing of monolithic parts with multiple functionalities. The research presented in this Dissertation results in the creation of knowledge in material extrusion AM technology with the length scale of production-grade to large-scale 3D printing machine those were used to enable the fabrication of multimaterial …

Fabrication And Testing Of Advanced Composites For Extreme Environments, Victoria Centeno

Open Access Theses & Dissertations

The following research focuses on the additive manufacturing and characterization of epoxy syntactic foams that utilize hollow carbon microspheres (CMS) and graphene-coated hollow carbon microspheres (GCMS) as fillers. The matrix that is utilized in this study is a thermoset epoxy resin, chosen for its high strength, low shrinkage, excellent adhesion to various substrates, effective electrical properties, chemical and solvent resistance, low cost, and low toxicity.1 CMS and GCMS were used as fillers for the properties they contribute to the overall epoxy syntactic foam, and can be seen in Fig.1.1. CMS consist of outer stiff carbon and inner gas, giving the …

Microstructural Evolution And Mechanical Properties Of L-Pbf Aerospace Alloys: Hydride- Dehydride Ti-6al-4v And Experimentally Heat-Treated Inconel 718, Jaime Varela

Open Access Theses & Dissertations

Experimental HIP and heat treatment cycles were applied to Laser Powder Bed Fusion fabricated Inconel 718 parts. Recent advances allow for rapid cooling in the HIPing chamber allowing one unit to perform HIP along with other heat treatment cycles such as solution annealing and ageing. Different cycles yield various effects on the porosity reduction as well as the growth of grain in the microstructure, consequently presented different mechanical properties. Specimens were therefore analyzed for density, microstructure, and tensile properties.

In addition, the mechanical and microstructural analysis of HDH Ti-6Al-4V was performed. The high cost of GA Ti64 material is a …

Effect Of Dopants On The Properties And Performance Of Gallium Oxide: Bulk Ceramics And Nanomaterials, Vishal Bhimrao Zade

Open Access Theses & Dissertations

A comprehensive investigation performed in order to understand the fundamental aspects of transition metal (TM) incorporation into Ga2O3, a wide band gap semiconductor with a huge potential for application in electronics, optics, micromechanics and optoelectronics. An approach is presented to tailor the structural, optical, electrical, mechanical properties of Ga2O3 ceramics and thin films. The tungsten (W) mixed Ga2O3 with variable W at% (Ga2-2xWxO3 ; 0.00 ≤ x ≤ 0.30) were synthesized by the high temperature solid state route involving a 2-step calcination process. The solubility limits and phase stability of the compounds are established. While solubility and phase stability occur …

Image Analysis Of Charged Bimodal Colloidal Systems In Microgravity., Adam J. Cecil

Electronic Theses and Dissertations

Colloids are suspensions of two or more phases and have been topics of research for advanced, tunable materials for decades. Stabilization of colloids is typically attributed to thermodynamic mechanisms; however, recent studies have identified transport or entropic mechanisms that can potentially stabilize a thermodynamically unstable colloidal system. In this study, suspensions of silsesquioxane microparticles and zirconia nanoparticles were dispersed in a nitric acid solution and allowed to aggregate for 8-12 days in microgravity aboard the International Space Station. The suspensions were subsequently imaged periodically at 2.5x magnification. Due to the inadequacy of existing image analysis programs, the python package “Colloidspy” …

Post Processing Of Electron Beam Melted Ti-6al-4v And Binder Jetted 17-4 Stainless Steel, Ahmad Omar Abu-Issa

Open Access Theses & Dissertations

An extensive assortment of HIP parameters have been altered on EBM fabricated Ti-6Al-4V and have shown that cooling rates of 103 oC/min from temperatures above and below the beta transus produced acicular alpha-prime martensite characteristic elongations < 10 %. Optimum yield strength (0.9 GPa), UTS (1.0 GPa) and elongation (~14 %) were achieved for slow cooling (at 102 oC/min) from 850 oC HIP which produced a dense, Widmanstatten alpha structure within the retained, as-fabricated columnar grains by alpha-prime decomposition. These results suggest that manipulation of AM process parameters to produce a small-grain, equiaxed microstructure, HIPed below the beta transus and slow cooled, will have a wide range of superior, isotropic mechanical properties corresponding to a Widmanstatten alpha microstructure within the equiaxed grains. Also, Binder Jetting printing parameters for differing PSD's of low-cost water-atomized 17-4 Stainless Steel were optimized in order to produce high dense parts. Densities ranging from 94-97.5% were achieved, and issues of inhomogeneous porosity were addressed using a fumed silica flow additive.

Aloe Vera Extract-Based Composite Nanofibers For Wound Dressing Applications, Raul Barbosa, Alexa Villarreal, Cristobal Rodriguez, Heriberto De Leon, Robert Gilkerson, Karen Lozano

Mechanical Engineering Faculty Publications

Natural, biocompatible, and biodegradable composite nanofibers made of Aloe vera extract, pullulan, chitosan, and citric acid were successfully produced via Forcespinning® technology. The addition of Aloe vera extract at different weight percent loadings was investigated. The morphology, thermal properties, physical properties, and water absorption of the nanofibers were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). The developed nanofiber membranes exhibited good water absorption capabilities, synergistic antibacterial activity against Escherichia coli, and promoted cell attachment and growth. Its porous and high surface area structure make it a potential candidate for wound dressing …

Analysis On Fuel Options For Scramjet Engines With The Study To Lower The Starting Mach Number, Sumantra Luitel, Gagan Dangi

Honors Theses

The main objectives of this report were to perform analysis of an ideal scramjet engine, to assess the influence of fuel on endurance factor, and the possibility of lowering the starting Mach Number of the scramjet. In the first part, an ideal cycle parametric analysis was conducted on three different fuels i.e. Liquid Hydrogen (LH2), Jet Propellant 7 (JP-7), and Rocket Propellant (RP-1), taking into account their availability, physical properties, current uses, and potential uses. The detailed analysis is done largely relying on a 9 step Parametric Cycle Analysis technique to study how fuel properties influence the variation of seven …

Centrifugally-Spun Ceramic/Carbon Composite Fibers And Their Use As Anode Materials In Li-Ion Batteries, Gabriel Gonzalez

Theses and Dissertations

The work in this thesis focuses in the study of Centrifugally Spun Short Fiber Composites and their Implementation as Alternate Anode Material in Li-Ion Batteries. Due to their high theoretical capacity, abundance, and environmental friendliness, metal oxides have been widely studied as alternate anode materials for lithium ion batteries (LIBs). In this research work, the processing of SnO2 and SnO2/TiO2 ceramic short fibers as well as flexible and porous metal oxide carbon fibers (FPMOCFs) by centrifugal spinning followed by an optimized coating technique is reported. In addition, the electrochemical performance of the composites was also investigated and is provided.

Study Of Particle Size Effect On The Performance Of Tio2 Nanoparticles As Lubricant Additives On Vegetable Oil-Based Nanolubricants, Dario F. Rodriguez

Theses and Dissertations

Recently there has been an increase in concern regarding the use of petroleum-based lubricants. This has created an interest in readily available biodegradable lubricants such as vegetable oils. This work evaluates the rheological and tribological performance of grapeseed, and sunflower oils altered with 5, 18, and 40 nanometer titanium dioxide (TiO2) nanoparticles at differing concentrations. Block-on-ring tests were performed using the ASTM G-077-05 standard procedure. The effect of nanoparticle size and concentration and shear rate on the viscosity were evaluated and the experimental data was compared to conventional models. Roughness tests were performed on the wear scar of the blocks …

Development And Characterization Of Nanofiber-Based Thermoelectric And Piezoelectric Composites, Julio Enrique Trevino

Theses and Dissertations

This study focuses on the development and characterization of nanofiber-based composites with the goal of developing flexible, lightweight, and cost effective thermoelectric and piezoelectric devices. The following materials were used in the development of the composites: polyvinylidene fluoride (PVDF) with polyaniline (PANI), polypyrrole (PPY), polyindole (PIN), polyanthranilic acid (PANA), polycarbazole (PCZ), polyacrylonitrile (PAN), functionalized multi-walled carbon nanotubes (MWCNT-COOH), and camphorsulfonic acid (CSA). Blends and in-situ polymerization techniques were utilized to increase the desired thermoelectric/piezoelectric response. Nanofiber systems were produced utilizing the Forcespinning® technique. The morphology, structure, electrochemical, thermal stability, thermoelectric, and piezoelectric performance was analyzed. All of the nanofiber PVDF/CP …

Assessing The Feasibility Of A Biofilter In Medium-To-High Scale Industries, Javier A. Garcia

Theses and Dissertations

The removal of volatile organic compounds, VOCs, from contaminated sources of air stream has become a major air pollution risk. Excessive amounts discharged to the atmosphere are highly risky to human health and to the environmental system. Demand for sustainable VOC control technologies has become crucial for the reduction of emissions. Biological treatments of waste gas streams, such as biofiltration, have proven to be cost effective and environmentally friendly compared to conventional pollution control technologies. The goal of this research is to simulate data for a given biofilter model, and to evaluate if it is economically and environmentally feasible to …

Modeling And Energy Simulation Of A Zero Energy Building: A Case Study For Florida, Mariana Migliori Favaretto

Theses and Dissertations

The study of energy consumption in buildings is an important area of research given the large share of building sector in the worldwide energy usage. The energy consumption of buildings has a high impact on carbon emissions, a greenhouse gas which has proved to play a major role in global warming. In the last decades, global warming has become an increasing concern and worldwide high energy demand have awaken a pressing quest towards improving building energy efficiency. Reducing buildings’ energy usage by implementing energy efficiency measures is one way towards a sustainable future for any country in the world. This …