Mechanical Engineering Commons^™

Impact Of Viscoelastic Properties Of Low Loss Printed Circuit Boards (Pcbs) On Reliability Of Wcsp Packages Under Drop Test, Akshay Boovanahally Lakshminarayana

Mechanical and Aerospace Engineering Theses - Archive

Reliability of electronic packages is a major concern as different failure modes are induced due to factors such as temperature loads, mechanical stresses, humidity, corrosion and so on. Finite element analysis (FEA) is often performed to assess reliability under different loading conditions such as thermal cycling, drop testing, power cycling and vibrational loads. Having accurate material property data is one of the key requirements to perform successful FEA study, and a significant amount of time and money is spent to perform accurate material characterizations. Lump modeling approach, where components are represented by a block and assigned effective properties, is commonly …

Measurement Of Change In Cte Of Pcbs Due To Single Phase Immersion Cooling And Impact Of Changed Properties Of Pcbs On Solder Joint Reliability Of Bga Package, Sameer Hemant Dhandarphale

Mechanical and Aerospace Engineering Theses - Archive

Oil immersion cooling in high-density data centers is emerging as an alternative for traditional air cooling because of the less power consumption, capacity to handle high power density and less space requirement. To adopt this technique extensively, effect of immersion on reliability of server components in dielectric coolant needs to be evaluated. One of the major reliability concerns in BGA package is 2nd level solder joint failure. The primary reason of solder joint failure is CTE mismatch between the PCB and the package. Also, difference in stiffness of the PCB and the package affects the solder joint reliability. As properties …

Design And Validation Of A Dynamic Pressure-Based Loading Device And 3d Strain Tracking Protocol For Ventral Hernia Modeling, Griffin Kivitz

McKelvey School of Engineering Graduate Student Theses & Dissertations

It is estimated that 350,000-500,000 ventral hernia repair surgeries are performed each year in the United States. While the long-term recurrence rate of ventral hernia repairs is not yet known, when tissues are exposed to the trauma of surgery, there is always the chance of recurrence. Commonly used ex vivo testing methods for determining the mechanical properties of the abdominal wall and biomaterials for hernia repair consist primarily of uniaxial and biaxial testing, which are not physiologically relevant loading environments. The need for a testing device that can exert physiologically relevant loads ex vivo to an abdominal wall is crucial …

Improvement Of Ultraviolet Digital Image Correlation (Uv-Dic) At Extreme Temperatures, Thinh Quang Thai

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Extreme temperature has increasingly played an essential role in design and operation of various engineering applications including spacecraft re-entry, hypersonic flight, next-generation nuclear reactors, and hot-fire rocket testing. To protect instruments against the harsh environments, it is preferable to use non-contacting measurements when monitoring the integrity of those mechanical structures. Digital Image Correlation (DIC) is a popular method which uses digital cameras in order to track motion thanks to images acquired before and after deformation. Displacements and strains are plotted over a full-field region which is conducive to identify highly risky zones. At high temperature, objects emit light which interferes …

Aerodynamic Interactions Of Synchronized Propellers, Nathan Welker, Samuel Johnson

Utah Space Grant Consortium

Emerging advances in electric-propulsion technology are enabling aircraft to use distributed electric propulsion (DEP) to increase efficiency and maneuverability. Distributed electric propulsion can also provide unique take-off and landing abilities which are not commonly found on traditional aircraft. The implementation of DEP effectively decreases the spacing between propellers, introducing complex aerodynamic interactions that are not well understood. This study aims to obtain experimental measurements of the flow fields of synchronized propellers at close-proximity in a side-by-side configuration using particle image velocimetry (PIV) in a wind tunnel. The results of this work will be focused on identifying the impact closely-spaced propellers …

Comparison Of Wake Expansion Methods For Use In Wake Expansion Continuation Optimization, Jared J. Thomas

Utah Space Grant Consortium

This paper presents a comparison of three methods for expanding the wake for use with wake expansion continuation (WEC) optimization. A process related to continuation optimization methods for reducing multi-modality in the wind farm layout optimization problem. A reduction in multi-modality is achieved by starting with an increased wake spread, while maintaining normal velocity deficits at the center of the wakes, and then reducing the wake spread for each of a series of optimization runs until the standard wake spread is used. Three wake expansion methods were tested: (1) increasing the wake expansion angle, (2) multiplying the wake diameter, and …

Monte-Carlo Methods And The Step-Back Kalman Filter For Orbital State Estimation, Louis Tonc

Utah Space Grant Consortium

This research assesses the performance of filtering schemes for tracking uncooperative satellites through space-based optical measurements, and identifies a simple and numerically stable methodology that ameliorates the poor performance of standard filtering schemes at a substantially reduced cost in comparison to nonlinear particle filter-based remedies. Traditional filtering schemes, such as the extended Kalman filter (EKF) and unscented Kalman filter (UKF), both diverge when tracking a resident space object (RSO) in geosynchronous orbit (GEO) when there is a long time duration between measurements. This divergence is identified as a consequence of nonlinearity in the dynamics and nonlinearity in the optical measurements, …

An Examination Into The Defining Characteristics Of Flexible Solar Aircraft Configurations Through Optimization, Taylor Mcdonnell

Utah Space Grant Consortium

This paper examines the defining characteristics of various solar aircraft configurations through gradient-based multidisciplinary design optimization. We first present a general gradient-based solar aircraft optimization framework which accounts for nonlinear aeroelastic effects resulting from structural flexibility. We then apply this framework to several discrete SR-HALE aircraft geometric, structural, and propulsion system configuration choices to determine the defining characteristics of each configuration choice.

Model Reference Predictive Adaptive Control For Large Scale Soft Robots, Phillip Hyatt, Curtis Johnson

Utah Space Grant Consortium

Past work has shown Model Predictive Control (MPC) to be an effective strategy for controlling continuum joint soft robots using rudimentary models, however the in-accuracies of these models often mean that an integration scheme must be combined with MPC. Presented in this work is a novel dynamic model formulation for continuum joint soft robots which is more accurate than the authors’ previous models yet remains fast enough for MPC. This model is based on the Piecewise Constant Curvature (PCC) assumption and a relatively new configuration representation and allows for computationally efficient simulation. Due to the difficulty in determining model parameters …

Ensuring Extramobile And Intramobile Motion On Cylindrical Developable Mechanisms, Jared Butler

Utah Space Grant Consortium

Developable mechanisms offer the ability to deploy to perform tasks then return to a hidden position along or interior to a predetermined developable surface. It is often advantageous for these mechanisms to not penetrate the surface along which they conform. This paper presents the limits of extramobile and intramobile motion (motion exterior to and interior to a developable surface). Three conditions are identified that determine a limit of extramobile and intramobile behavior. It is shown that the more difficult of these conditions to predict is never reached prior to the more simple cases. This is demonstrated for all possible Grashof …

Influence Of Electrode Height On Carbon Nanotube Electrochemical Biosensors, Benjamin J. Brownlee

Utah Space Grant Consortium

High sensitivity of electrochemical sensors enables the detection of low concentrations of target analyte. Being able to quickly and accurately detect low concentrations of proteins at point-of-care allows for results to be analyzed more easily and effectively. Having high surface area allows for more analyte to be detected, possibly leading to increased sensitivity. Vertically-aligned carbon nanotubes (VACNTs) were patterned into interdigitated electrodes (IDEs) and then functionalized with the representative protein streptavidin to demonstrate sensing of biotin. Three electrode heights were investigated to determine the influence of electrode height on sensor sensitivity. Cyclic voltammetry and electrochemical impedance spectroscopy were used to …

Evolutionary Nonlinear Model Predictive Control On A Fixed-Wing And Multirotor, Jaron Ellingson, Matthew Haskell

Utah Space Grant Consortium

Real-time model predictive control (MPC) is limited to short time horizons and linear systems because the optimization complexity is too large with long time horizons and nonlinear systems. For this reason, MPC is typically accomplished using linearized models and convex optimization solvers. We seek to explore evolutionary algorithms allowing for nonlinear models and constraints, non-convex costs, and extended time horizons.

Our contributions include extending nonlinear evolutionary MPC to flight vehicles, fixed-wing and multirotor UAVs, as well as enhancing the evolutionary algorithm. We also intend to parameterize the design space of the optimization to reduce solve times. These contributions validate the …

Comprehensive Second-Order Adjoint Sensitivity Analysis Methodology (2nd-Asam) Applied To A Subcritical Experimental Reactor Physics Benchmark: V. Computation Of Mixed 2nd-Order Sensitivities Involving Isotopic Number Densities, Ruixian Fang, Dan Gabriel Cacuci

Faculty Publications

This work applies the Second-Order Adjoint Sensitivity Analysis Methodology (2nd-ASAM) to compute the mixed 2nd-order sensitivities of a polyethylene-reflected plutonium (PERP) benchmark's leakage response with respect to the benchmark's imprecisely known isotopic number densities and the other benchmark imprecisely known parameters, including: (i) the 6 × 180 mixed 2nd-order sensitivities involving the total microscopic cross sections; (ii) the 6 × 21,600 mixed 2nd-order sensitivities involving the scattering microscopic cross sections; (iii) the 6 × 60 mixed 2nd-order sensitivities involving the fission microscopic cross sections; and (iv) the 6 × 60 mixed 2nd-order sensitivities involving the average number of neutrons produced …

Portable Calorimeter For Fire Experiments, Kayla Collins, Kara Hewson, Christopher Chen, Joel Keddie

Mechanical Engineering

Executive Summary

An oxygen consumption calorimeter works by measuring the heat release rate of a burning substance. This value is calculated by measuring the oxygen and byproducts in smoke from afire.In order to get these values two types of sensors were used. A non-dispersive infrared sensor (NDIR) that measured CO and CO2 and a zirconium O2 sensor were used to find their respective gas concentrations.The design to calculate the heat release rate is focused on maximizing sensor accuracy and portability while simplifying the manufacturing by using off-the-shelf components. The goal included making the system simple to recreate and package in …

Flash Lab: A High-Speed Imaging Laboratory, Cody D. Hatch

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

To help students become better acquainted with high-speed instrumentation and measurement techniques, a high-speed imaging laboratory for the College of Engineering is equipped with a high-speed camera and schlieren imaging device. The laboratory will be used for labs in classes, such as Instrumentation, Thermal/Fluids Lab, Experimental Solids, and Mechanical Experiments. In addition, graduate students will use it for research purposes. The laboratory also has the potential to have a course associated with it that would include the image processing techniques for a variety of applications (e.g., a course on high-speed imaging). The scope of this project will be to create …

Hemodynamic Effects On Aortic Development Due To Outflow Tract Banding, Humza Ismail

McKelvey School of Engineering Graduate Student Theses & Dissertations

Hemodynamic forces drive remodeling of the early cardiac system in embryonic development. Perturbations of normal cardiac blood flow can cause the formation of defects and malformations within the cardiac system. Specifically, changes in hemodynamics can cause the formation of different congenital heart defects. The formation of heart defects has been studied; however, vasculature specific defects caused by changes in blood flow patterns in the early cardiac system have not been studied to the same degree. In this thesis, the effects of hemodynamic changes on arterial development were studied. Outflow tract banding (OTB) was used to cause a local increase in …

Additive Manufacturing And How 3d Printing Is Fighting Covid-19, Raghavan Srinivasan, Ahsan Mian, Joy Gockel, Laura M. Luehrmann

Mechanical and Materials Engineering Faculty Publications

This is the fourth installment in the Shelter in Place (SiP) Lecture series. This installment covers the creative ways that 3D printing has supported efforts to combat the pandemic. It covers the basics of what 3D printing is, some of the various creative projects that have used 3D printing to combat the pandemic, among other topics and questions by the pandemic.

Utilization Of Recycled Filament For 3d Printing For Consumer Goods, Alexa Peterson

Apparel Merchandising and Product Development Undergraduate Honors Theses

The 3D printing market has been used in a wide variety of manufacturing industries including textile and apparel. Many consumers can now own a personal 3D printer at home for recreational printing. There are even websites dedicated to 3D printing patterns made by consumers. However, the materials used in the 3D printing process pose a problem for the environment due to their plastic-based nature. 3D printing is a layered process with each layer being printed depending on the layer below it for strength and stability. During the 3D printing process, great amounts of waste are produced as a result of …

Static Pressure Recovery Effects Of Conical Diffusers With Swirling Inlet Flow, James Ray Wright Iii

All Theses

Conical diffusers are used in hundreds of engineering applications in various industries. Some of the operating conditions that they operate under cause swirling flow to enter the diffuser. It is generally well documented that the addition of swirl to the flow of a diffuser allows for greater divergence angles without wall separation, resulting in better overall performance of the diffuser and the machine it’s attached to. It is also known that as swirl strength is increased, the flow will eventually breakdown, resulting in internal flow recirculation and decreased diffuser performance. However, the relationship between the diffuser geometry and its performance …

Design Optimization Of An Elastically Supported Multi-Beam Rotordynamic System To Minimize Flexural Response With Considerations For Robustness, Bret R. Hauser

Mechanical and Aerospace Engineering Dissertations - Archive

Modern rotating machines are often required to operate with a small physical footprint and/or overall weight; necessitating that they utilize wide-ranging shaft speed to accomplish needed power levels. It is not uncommon that these designs also be required to support operation through a speed range encompassing multiple Critical Speeds while also limiting flexural vibrations to acceptable levels. Design optimization of this class of problem can be particularly difficult in that responses can be highly multi-modal and, when coupled with Finite Element (FE) solvers meet the conditions of a High Dimensional, Computationally Expensive Black Box (HEB) system. Because of this, some …

Machine Learning Modeling Of Horizontal Photovoltaics Using Weather And Location Data, Christil Pasion, Torrey Wagner, Clay Koschnick, Steven Schuldt, Jada Williams, Kevin Hallinan

Mechanical and Aerospace Engineering Faculty Publications

Solar energy is a key renewable energy source; however, its intermittent nature and potential for use in distributed systems make power prediction an important aspect of grid integration. This research analyzed a variety of machine learning techniques to predict power output for horizontal solar panels using 14 months of data collected from 12 northern-hemisphere locations. We performed our data collection and analysis in the absence of irradiation data-an approach not commonly found in prior literature. Using latitude, month, hour, ambient temperature, pressure, humidity, wind speed, and cloud ceiling as independent variables, a distributed random forest regression algorithm modeled the combined …

Additive Manufacturing Of Dense We43 Mg Alloy By Laser Powder Bed Fusion, Holden Hyer, Le Zhou, George Benson, Brandon Mcwilliams, Kyu Cho, Yongho Sohn

Mechanical Engineering Faculty Research and Publications

WE43 is a high-strength, corrosion-resistant Mg-alloy containing rare earths such as Y and Nb, and has potential for many lightweight structural or bioresorbable prosthetic applications. In this study, additive manufacturing of dense WE43 alloy by laser powder bed fusion (LPBF) from gas atomized powders has been accomplished through studies involving single track scan of wrought WE43, parametric variation of LPBF, microstructural analysis and mechanical testing, both in compression and tension. The Archimedes method and image analyses from optical micrographs were employed to document the LPBF of dense (>99 % relative density) WE43 using optimum parameters of 200 W laser …

Mathematical Modeling Of A Variable Mass Rocket’S Dynamics Using The Differential Transform Method, Ashwyn Sam

Honors Theses

In this paper, the mathematical modelling of a rocket with varying mass is investigated to construct a function that can describe the velocity and position of the rocket as a function of time. This research is geared more towards small scale rockets where the nonlinear drag term is of great interest to the underlying dynamics of the rocket. A simple force balance on the rocket using Newton’s second law of motion yields a Riccati differential equation for which the solution yields the velocity of the rocket at any given time. This solution can then be integrated with respect to time …

Materials-Processing Relationships For Metal Fused Filament Fabrication Of Ti-6al-4v Alloy., Paramjot Singh

Electronic Theses and Dissertations

Additive manufacturing (AM) is at the mainstream to cater the needs for rapid tooling and small-scale part production. The metal AM of complex geometries is widely accepted and promoted in the industry. While several metal AM technologies exist and are matured to a level where expectation in terms of design and properties are possible to realize. But the metal AM suffers from the heavy expense to acquire equipment, isotropic property challenges, and potential hazards to work with loose reactive metal powder. With this motivation, the dissertation aims to develop the fundamental aspects to print metal parts with bound Ti-6Al-4V powder …

Selective Laser Melting 17-4 Ph Stainless Steel And The Effect Of Varied Thermal Treatments On Fatigue Behavior., Sean Daniel Dobson

Electronic Theses and Dissertations

Fatigue failure is the leading source of loss in industry. In order for new means of manufacturing to move towards mainstream use a complete understanding of material and mechanical behavior must be gained. This endeavor seeks to aide in that task by observing the fatigue behavior of selective laser melting (SLM) additive manufacturing (AM) specimens and the effect of differing thermal treatment conditions for an optimized AM process. Stainless steel 17-4 PH specimens were fabricated using SLM AM and thermally treated to three conditions: as-built, solutionized and hardened, and direct hardened. These specimens were characterized for material (powder quality, density, …

Assessing The Impact Of Drop Velocity And Spacing In Binder Jetting To Improve Printing In Novel Powders And New Environments, Trenton Colton

Utah Space Grant Consortium

Binder Jetting (BJ) is a low-cost Additive Manufacturing (AM) process that uses inkjet technology to selectively bind particles in a powder bed. The interaction of the binder droplets with the powder is essential to the process. This is a complex interaction in which picoliter-sized droplets impact powder beds at velocities of approximately 10 m/s. The binder partially fills the voids between the powders. The fraction of void space filled with binder is the saturation and is a key parameter in BJ. The effects of printing parameters such as droplet velocity, size, and spacing on saturation levels are unknown. This study …

Effect Of Superhydrophobic Surface Microstructure On Transient Jet Impingement Cooling, D. Jacob Butterfield, John Morris

Utah Space Grant Consortium

Jet impingement is an effective method of rapid surface cooling, and is highly dependent on surface condition and properties. Here, silicon surfaces are modified by ion-etching different micropatterns (posts or holes) on one side and coated with Teflon to make them superhydrophobic (SH). The other side of the surface has a screen-printed resistance heater. Surfaces are heated to temperatures between 200 to 320 °C, and then impinged on by a pure water jet at room temperature with flow rates ranging from 6 to 18 mL/s. Results show that there is little effect of microstructure, although hole surfaces and shorter microstructures …

Design And Demonstration Of Automated Technologies For The Fabrication And Testing Of Pem Fuel Cell Systems, Vladimir Gurau, Daniel Cox, Devin C. Fowler, Matthew Carter, Adedayo Ogunleke

Manufacturing Engineering: Faculty Publications (2015-2023)

This paper describes the research efforts at Georgia Southern University to develop robotic technologies for the fabrication of fuel cell components and stacks, as well as the design and fabrication of a High Temperature Proton Exchange Membrane Fuel Cell (HT-PEMFC) power system to be used as motive power and auxiliary power unit (APU) for a long range, unmanned, fully autonomous forest rover. The paper describes a manufacturing workcell consisting of a Yaskawa Motoman SDA5F dual arm robot with machine vision used for sorting, reorientation and stacking fuel cell components in presenters in preparation for their subsequent robotic assembly in fuel …

Experimental Evaluation Of Heat Leak And Convective Heat Transfer In A Household Freezer., Catherine E. Berghuis

Electronic Theses and Dissertations

Heat leak into household refrigerated cabinets is a key driver affecting energy consumption and efficiency of the cooling system. Additionally, knowledge of heat transfer coefficients of internal surfaces is valuable in the development of cabinet and system level performance simulations. Several studies have examined heat leak of refrigeration units using heat flux sensors (HFS); however, no such studies have used heat flux measurements to derive convective heat transfer coefficients of the refrigerated unit walls. The goal of this study is to evaluate the use of HFS to quantify heat leak into a 490-liter freezer and determine the wall convective heat …

Influences Of Material Extrusion Additive Manufacturing (Meam) Parameters And Additives On Polyvinylidene Fluoride (Pvdf) Properties., Niknam Momenzadeh

Electronic Theses and Dissertations

Beyond the beneficial characteristics of smart polymers associated with all polymers such as flexibility and cost fabrication, smart materials exhibit multifunctional behaviors. The prospect of integrating structural and sensing/actuation capabilities into a single structure gives design engineers an ability to innovate highly novel, multi-functional creations. Polyvinylidene Fluoride (PVDF) is one of the widely used multi-functional materials which offers a variety of desirable material properties. It possesses exceptional chemical and UV resistance, biocompatibility, low processing temperature and affordable price making it a competitive choice for many commercial applications. In addition, among polymers, PVDF is simply the most dominant piezoelectric polymer. On …