Mechanical Engineering Commons^™

Designed Extrudate For Ceramic Additive Manufacturing, Devin Mcmillen

Masters Theses

"The objective of this thesis work was to design ceramic paste systems that assist in achieving a high theoretical density ( > 95%) after deposition by a novel additive manufacturing process, i.e. Ceramic On-Demand Extrusion (CODE). The work is encompassed in five main sections: Sections 1 and 2 provide an introduction and literature review of relevant topics for the following sections of experimentation. Section 3 provides an analysis of a reaction chemistry to identify three discrete materials that could be combined via CODE and result in zirconium diboride (ZrB₂) post-sintering. Section 4 describes the development of a high solids …

Smart Augmented Reality Instructional System For Mechanical Assembly, Ze-Hao Lai

Masters Theses

"Quality and efficiency are pivotal indicators of a manufacturing company. Many companies are suffering from shortage of experienced workers across the production line to perform complex assembly tasks such as assembly of an aircraft engine. This could lead to a significant financial loss. In order to further reduce time and error in an assembly, a smart system consisting of multi-modal Augmented Reality (AR) instructions with the support of a deep learning network for tool detection is introduced. The multi-modal smart AR is designed to provide on-site information including various visual renderings with a fine-tuned Region-based Convolutional Neural Network, which is …

Enhancement Of Performance Of Micro Direct Ethanol Fuel Cells By Structural Modification, Sindhuja Valluri

Masters Theses

“Direct Ethanol Fuel Cells (DEFC’s) are becoming more important in current energy conversion devices because of their higher efficiency compared to other fuel cells. However, the performance of current DEFC’s is not efficient in providing energy to meet increasing energy demand. The objective of this work is to make the cell compact and at the same time improve performance. For this purpose, we have removed gasket and endplates to make structure compact and increased surface area by developing a new corrugated structure. This work also uses 3D printing technology Fused Deposition Modeling (FDM) to make pocket backing case to improve …

Multiscale Approaches Toward Advanced Lithium-Ion Battery: From Nano To Meso Scale, Susmita Sarkar

Masters Theses

“Battery performance and its degradation are determined by various aspects such as the transport of ions and electrons through heterogeneous internal structures composed of constituent particles, kinetic reactions at the interfaces, and a corresponding interplay between mechanical, chemical, and thermal responses. Further, modern battery materials require a variety of engineering processes such as coating, doping and mixing. As a result, in order to fully understand the behavior of the battery material and improve battery performance, it is necessary to understand and control the individual particle behavior and then connect it to the electrode. This study elucidated the physical phenomena associated …

Numerical Modeling Of Capillary-Driven Flow In Open Microchannels: An Implication Of Optimized Wicking Fabric Design, Mehrad Gholizadeh Ansari

Masters Theses

"The use of microfluidics to transfer fluids without applying any exterior energy source is a promising technology in different fields of science and engineering due to their compactness, simplicity and cost-effective design. In geotechnical engineering, to increase the soil's strength, hydrophilic wicking fibers as type of microfluidics have been employed to transport and drain water out of soil spontaneously by taking advantage of natural capillary force without using any pumps or other auxiliary devices. The objective of this study is to understand the scientific mechanisms of the capability for wicking fiber to drain both gravity and capillary water out of …

Model Predictive Power Management Of A Hybrid Electric Propulsion System For Aircraft, Tyler J. Wall

Masters Theses

This work presents the switched optimal power flow control for an aircraft with a hybrid electric propulsion system. The propulsion system is a switched system that operates in either of two modes: (i) battery discharging and electric motor propelling and (ii) battery charging and electric motor generating. The aircraft model and components that form the hybrid propulsion system are modeled as either an algebraic power source/sink or as a dynamic model with appropriate power and state interconnections. With the system model defined, a model predictive control power management strategy is set fourth which minimizes a performance index that includes altitude …

Finite Element Analysis Of Tibiofemoral Contact Mechanics, Erika Fojtik

Masters Theses

The effects of lateral meniscus posterior root avulsions (LMPRA) have been studied in combination with meniscofemoral ligament (MFL) deficiencies. The purpose of this study is to validate a set of biomechanical finite element analyses against previously reported experimental results to predict the contact area and peak contact pressure in the lateral tibiofemoral compartment of the knee during lateral meniscal root avulsions in combination with MFL deficiencies. Patient specific MRI data was used to develop finite element models for three distinct testing conditions: 1) intact, 2) lateral meniscus posterior root avulsion, and 3) lateral meniscus posterior root avulsion with deficient meniscofemoral …

Atmospheric Microbial Community Sampling System For Varying Altitude Collection, Kenneth David Domingue

Masters Theses

The study of airborne microbial communities in the vertical atmosphere is an area of research in which very little data has been collected and analyzed. Developing a vehicle to house biological sampling equipment that collects, and mitigates contamination is required by a team of biology researchers to perform sampling of atmospheric microbial communities. This study uses a sampler box that is attached to aerostatic vehicles: zero pressure balloons and tethered balloon/kite structures. Zero pressure balloons are used for sampling at altitudes above 150 m above sea level, and tethered balloon/kite structures are used for sampling at 30 m and 150 …

Development Of Empirical And Virtual Tools For The Study Of Bicycle Safety, Brent Kostich

Masters Theses

Bicycles have been used as a form of non-motorized transportation for several hundred years. Recently, their use in the transportation realm has been reinvigorated because of growing population densities and efforts to improve environmental sustainability. However, a large deterrent for public use of the bicycle is concern over its level of safety in the transportation environment. The goal of this thesis is to develop two complementary research tools that advance the study of bicycle safety factors.

First, an instrumented probe bicycle (IPB) is constructed from the ground up. The bicycle is outfitted with an array of sensors that are integrated …

Investigation Of Measured Cane Vibrations For Prediction Of Blind Pedestrian Performance In Surface Preview Tasks, Aaron Dean

Masters Theses

The white cane is the primary navigation tool used by many blind pedestrians, but the basic design of the cane has not changed since the 1940s. A greater understanding of the factors affecting cane performance is essential in improving the design and performance of these canes. One aspect of performance is surface texture discrimination. A study is performed to determine the effect of cane rigidity and cane swipe speed on the ability of a user to select the rougher of two surfaces with different textures. Two methods are developed to select the rougher surface using only the measured cane vibration. …

A Virtual Reality Based Powered Wheelchair Simulator, Yuliia Sergeeva

Masters Theses

Power wheelchairs provide great assistance for people with locomotion disabilities. However, for those who have tremor, operation of the wheelchair can be challenging and result in a chance to get into an accident. The focus of this research project is to create a semi-virtual reality power wheelchair driving simulator that can be used for testing a notch filter for tremors in a safe laboratory environment and obtain data on human operator movements for future mathematical modeling. The simulator incorporates a realistic and immersive virtual environment and power wheelchair movement into it. For the experiment, a physical PWC joystick was connected …

Effect Of Design Parameters On Thermal Performance Of A Vane Type Disc Brake Rotor, Yogesh Satish Dalal

Masters Theses

The ever-increasing need of effective transportation puts automobile manufacturers in a situation of continuous improvement and innovate the safety systems. The brake system of an automobile has always been considered as one of the most critical active safety systems. Thermal characteristics of the brake are an important aspect to consider for brake disc durability and performance. The convective cooling of a brake disc is an important factor since design changes in the brake rotor can significantly improve cooling characteristics. The focus of this research is to study and optimize the disc brake rotor for a given heat dissipation rate and …

Ti-Fe Intermetallics Analysis And Control In Joining Titanium Alloy And Stainless Steel By Laser Metal Deposition, Wei Li

Masters Theses

"Direct fusion joining titanium alloy and stainless steel can cause brittle Ti-Fe intermetallics which compromise the mechanical properties of diffusion bonds between titanium alloys and stainless steel. Therefore, filler metals are required as transition layers. In this research, stainless steel metallic powder was directly deposited on the titanium alloy substrate by laser beam, the Ti-Fe intermetallic phases formed in this process were investigated through analyzing fracture morphology, phase identification, and Vickers Hardness Number (VHN). After that, Laser Metal Deposition (LMD) was applied to explore a new fabricating process to join Ti6Al4V and SS316. A transition composition route was introducedTi6Al4V → …

Dynamic Electromechanical Characterization Of Ferroelectrics At Cryogenic Temperatures, William Kent Hays

Masters Theses

"Electromechanical coupling in ferroelectric materials has given rise to a myriad of technological applications. Through the complex domain structure of ferroelectrics materials, which are typically stiff and have low damping, can exhibit significant structural damping. The applications for a material with a relatively large Young’s modulus and the ability to damp out vibrations would be useful for structures, more specifically, aerospace structures. The dynamic mechanical properties of ferroelectrics, particularly mechanical properties while an electric field is applied, are not well understood. This is due in part to the lack of experimental methods to measure such properties. Even with recent advancements …

Diffusion And Mechanical Characterization Of Nanoparticle-Enabled Diffusion Controlled Materials, Joseph Louis Volpe

Masters Theses

"Nanoparticle-enabled diffusion control has been shown to rapidly refine multiphase microstructures during slowly cooled casting. This thesis characterizes the diffusion and the mechanical properties of nanoparticle-enabled diffusion controlled materials. To characterize diffusion properties, in situ characterization is performed to verify the nanoparticle enabled diffusion control mechanism. Materials with nanoparticles were observed to decrease the diffusion coefficient by at least one order of magnitude under similar melting conditions as compared to materials without nanoparticles. To understand mechanical properties, the nanoparticles that assembled at the growing interface were characterized under mechanical tensile stress. Nanoparticle-enabled interfaces were observed to improve the interface bond …

Cathodic Protection Measurement Through Inline Inspection Technology Uses And Observations, Briana Ley Ferguson

Masters Theses

"This research supports the evaluation of an impressed current cathodic protection (CP) system of a buried coated steel pipeline through alternative technology and methods, via an inline inspection device (ILI, CP ILI tool, or tool), in order to prevent and mitigate external corrosion. This thesis investigates the ability to measure the current density of a pipeline's CP system from inside of a pipeline rather than manually from outside, and then convert that CP ILI tool reading into a pipe-to-soil potential as required by regulations and standards. This was demonstrated through a mathematical model that utilizes applications of Ohm's Law, circuit …

A Study Of Acoustic Reflections To Determine The Location, Size, Shape, And Orientation Of Reflecting Objects, Brandon M. Heller

Masters Theses

This study was conducted to examine the properties of sound in relation to echolocation, specifically in relation to its use by humans. Through my thesis, objects of varying shape and size were subjected to a sound wave to determine details about the object from the reflected sound. The shapes' comparisons were conducted at varying distances, measuring the intensity of the returning sound wave at several frequencies. The results demonstrated a correlation between the intensity of the sound in regards to distances, area of the reflector, and the shape of the reflector.

Error Mapping Of Build Volume In Selective Laser Melting, Ninad Kulkarni

Masters Theses

“Selective laser melting is one of the commonly used additive manufacturing processes employed for production of functional part. Therefore, quality aspects such as dimensional accuracy have become a point of great interest. Like all of the other additive manufacturing processes selective laser melting process suffers from the issue if having wide range of process parameters making the process control a complex task. Additionally, issues specific to the selective laser melting process such as position dependency of accuracy of the part, makes it difficult to predict the resulting dimensional inconsistencies in the part manufactured by this processes. This research is an …

Wrinkling Of Functionally Graded Sandwich Structures Subject To Biaxial And In-Plane Shear Loads, Harold Costa

Masters Theses

"Benefits of a functionally graded core increasing wrinkling stability of sandwich panels have been demonstrated in a recent paper [1] where a several-fold increase in the wrinkling stress was observed, without a significant weight penalty, using a stiffer core adjacent to the facings. In the present paper wrinkling is analyzed in case where the facings are subject to biaxial compression and/or in-plane shear loading and the core is arbitrary graded through-the-thickness. Two issues addressed are the effect of biaxial or in-plane shear loads on wrinkling stability of panels with both graded and ungraded core and the verification that functional grading …

Design And Analysis Of A Passive Heat Removal System For A Small Modular Reactor Using Star Ccm+, Raymond Michael Fanning

Masters Theses

"Next generation nuclear power plants, specifically small modular reactor designs, are the best alternative to fossil fuels for power generation due to their power density and low carbon emissions and constant awareness of safety concerns. A promising safety feature of new designs is the removal of heat by passive systems in accident scenarios. The passive systems require no moving parts and no intervention by personnel. These systems must be accurately simulated for better understanding of the heat transport phenomena: natural convection cooling. Due to the fact that most work developing these passive heat removal systems are proprietary information, a passive …

Bio-Inspired Flow Fields For Pem Fuel Cells- Decoupling Pressure And Distribution Effects On Performance And Identifying Design Opportunities, Joshua David Heck

Masters Theses

"The performance of Polymer Electrolyte Membrane Fuel Cells (PEMFCs) is significantly impacted by flow distributor geometry. The effects of flow distributor geometry on PEMFCs was explored in two ways in this study. Firstly, the relative effects of pressure and distribution characteristics of different flow fields on fuel cell unit and system level performance were considered. A method of decoupling these effects was proposed and demonstrated by application to the traditional serpentine and parallel flow field designs.The performance of these two designs were modeled computationally and it was shown that, of the 17% better performance of the serpentine design, 12% was …

Cyber-Physical Manufacturing Cloud: An Efficient Method Of Building Digital Twin For 3d Printer By Adapting Mtconnect Protocol, Liwen Hu

Masters Theses

"The common modeling of a virtual machine is using an information model to describe the physics of machines. The integration of digital twins into productive cyber-physical cloud manufacturing (CPCM) systems imposes strict requirements such as reducing overhead and saving resources for the systems. In this paper, we investigate a new method for building cloud-based digital twins (CBDT), which can be adapted to the CPCM platform. Our method helps reduce computing resources in the processing center and guarantees the fastest speed of the interactions between the human users and physical machines. We introduce a knowledge resource center (KRC) built on a …

Experimental And Numerical Study Of Dysphagia, Yash G. Potdar

Masters Theses

Dysphagia, meaning difficulty in swallowing, is a symptom of disease that occurs in young children and elderly people. It occurs particularly due to two reasons, weak neural network and/or deformities in oral section/s. The Helen DeVos Children’s Hospital’s Intensive Feeding Program takes care of children suffering from Dysphagia. In order to make the swallowing process easier and in some cases safer, thickener is added to the liquids. Depending on the requirement of thickness, the amount of thickener is varied. Although the directions to prepare the mixtures are given by the thickener product company, the required thickness is not achieved when …

Development Of An Analytical Model For Beams With Two Dimples In Opposing Directions, Mofareh H. Ghazwani

Masters Theses

Structures such as beams and steel plates can produce potentially high levels of unwanted vibrations and noises in the environment. A method of improving the vibration and acoustic characteristics of beams based on introducing dimples on its surfaces will be presented in this study. This method focuses on creating two dimples in the same and opposite direction on beam’s surface where the effect of dimples on the change in beam’s natural frequencies is the problems of interest.

A boundary value model (BVM) is developed for a beam with two dimples and subjected to various boundary conditions using Hamilton’s Variational Principle. …

A Genetic Algorithm Incorporating Design Choice For The Preliminary Design Of Unmanned Aerial Vehicles, Kenneth Michael Mull

Masters Theses

Unmanned Aerial Vehicles (UAVs) are currently at the forefront of aerospace technologies. The design of these aircraft is complex and often performance characteristics are coupled to multiple design attributes. At the early design phase both discrete and continuous design choices are present limiting the feasibility of traditional derivative based optimization techniques. In place of these methods, the design space can be explored using a genetic algorithm that mimics the process of natural selection, providing a capable and reliable base airframe constructed from the required performance metrics. By incorporating a genetic multidisciplinary optimization algorithm early in the conceptual design phase, aircraft …

Design, Modeling And Simulation Of A Thermoelectric Cooling System (Tec), Pooja Iyer Mani

Masters Theses

Thermoelectric Devices are solid state devices which directly convert thermal energy to electrical energy and vice versa. In the recent past, a lot of effort has been made to improve the performance and also the power generated by a thermoelectric device. This is done by attaching heat sinks on either sides of the device. Optimizing heat sinks improves the overall efficiency of it but on the other hand the device also has to be optimized. TECs are mostly used for electronic cooling where the heated electronic devices serve as target that needs to be cooled while air acts as a …

Modeling, Optimizing And Testing Thermoelectric Generators For Liquid-To-Liquid Low Grade Waste Heat Recovery, Ali Eyddan Hamil

Masters Theses

The use of thermoelectric generators (TEGs) for producing electricity from low grade waste heat is thought to be a great solution in the future to reduce the power generation cost because of their advantages of reliability and environmental friendliness. Therefore, the current project aims to study thermoelectric generators for low grade waste heat recovery. In this work, a single unit cell of liquid to liquid thermoelectric generator attached with heat exchangers (heat sinks) is modeled using an internal flow. Its optimum design is obtained based on heat sink optimization and the optimal design method. An analytical model of four unit …

Analytical Study Of Miniature Thermoelectric Device, Mohammed Dhannoon

Masters Theses

Miniature thermoelectric devices (TE) have been regarded as hopeful devices to attain efficient cooling in microprocessors and other small-scale devices. To recognize the performances of miniature thermoelectric coolers, a thermoelectric cooling module is theoretically analyzed. Particular attention is paid to the impact of the thermoelectric element length effect and the substrate material type influence on the cooling performance. The electrical contact resistance and thermal contact are taken into account.

Furthermore, miniature thermoelectric is compared with large thermoelectric, and effective material properties of miniature thermoelectric are studied. The obtained results also demonstrate power density (cooling/heating power per unit area of the …

Optimal Design Of Automotive Exhaust Thermoelectric Generator (Aeteg), Hassan Fagehi

Masters Theses

A consumption of energy continues to increase at an exponential rate, especially in terms of automotive spark ignitions vehicles. About 40% of the applied fuel into a vehicle is lost as waste exhaust to the environment. The desire for improved fuel efficiency by recovering the exhaust waste heat in automobiles has become an important subject. The thermoelectric generator (TEG) has the potential to convert exhaust waste heat into electricity as long as it is improving fuel economy. The remarkable amount of research being conducted on TEGs indicates that this technology will have a bright future in terms of power generation. …

Experimental Characterization And Simulation Of Carbon Nanotube Strain Sensing Films, Nagendra Krishna Chaitanya Tummalapalli

Masters Theses

Carbon Nanotubes (CNTs) have excellent mechanical, electrical and electromechanical properties. These properties led to a lot of novel applications. Due to change in electrical properties under mechanical loading, these composites have potential applications in strain sensors, when these are fabricated as films. CNT-based films are commonly fabricated using different physical and chemical techniques based on the property requirements governing those applications. In this work, CNT films were prepared using wet chemical based methods and chemical vapor deposition techniques.

Plasma chemical vapor deposition using microwave power is used in the first method to deposit films on silicon substrates, using Nickel film …