Mechanical Engineering Commons^™

A Convolutional Neural Network (Cnn) For Defect Detection Of Additively Manufactured Parts, Musarrat Farzana Rahman

Masters Theses

“Additive manufacturing (AM) is a layer-by-layer deposition process to fabricate parts with complex geometries. The formation of defects within AM components is a major concern for critical structural and cyclic loading applications. Understanding the mechanisms of defect formation and identifying the defects play an important role in improving the product lifecycle. The convolutional neural network (CNN) has been demonstrated to be an effective deep learning tool for automated detection of defects for both conventional and AM processes. A network with optimized parameters including proper data processing and sampling can improve the performance of the architecture. In this study, for the …

Wireless Power Transfer In Autonomous Mobile Microgrids, Carl Greene

Dissertations, Master's Theses and Master's Reports

The ability to autonomously dock unmanned ground vehicles plays a key role in mobile micro-grids, where efficient power transfer is paramount. The approach utilized in this work allows for near-field wireless power transfer in remote locations with minimal support. Establishing a micro-grid power system connection autonomously using wireless power eliminates the arduous task of designing a complex, multiple degrees of freedom (MDOF) robotic arm. The work presented in this thesis focuses on both the hardware and software within the micro-grid system. This particular near-field wireless system consists of a primary and secondary set of modules, comprised of Litz wire coils, …

An Experimental Study Towards Underwater Propulsion System Using Structure Borne Traveling Waves, Shreyas Suhas Gadekar

Dissertations, Master's Theses and Master's Reports

The method of generating steady-state structure-borne traveling waves underwater in an infinite media creates abundant opportunities in the field of propulsive applications, and they are gaining attention from several researchers. This experimental study provides a framework for harnessing traveling waves in a 1D beam immersed under quiescent water using two force input methods and providing a motion to an object floating on the surface of the water.

In this study, underwater traveling waves are tailored using structural vibrations at five different frequencies in the range of 10Hz to 300Hz. The resulting fluid motion provides a propulsive thrust that moves a …

Permeability, Structural Changes, Flow Regime Transitions In Fuel Cell Catalyst Layers And A Model For Predicting Trapped Saturation For Two-Phase Flow In Porous Media, Karrar Takleef Alofari

Dissertations, Master's Theses and Master's Reports

Proper water management in Proton Exchange Membrane (PEM) fuel cell is important to achieve high performance. Understanding the percolation of the produced water at the cathode catalyst layer (CL) is critical for any robust water management technique. In this study, an ex-situ experimental setup is used to study percolation in the CL at different injection rates and relative humidity (RH) conditions. The results show that increasing the flow rate force the liquid to flow through the bulk of the pores due to the dominant viscous effect. On the other hand, at low injection rates, the capillary becomes dominant and liquid …

Solute Concentration Effects On Microstructure And The Compressive Strength Of Ice-Templated Sintered Lithium Titanate, Rohan Parai, Ziyang Nie, Raina Hempley, Gary M. Koenig Jr., Dipankar Ghosh

Mechanical & Aerospace Engineering Faculty Publications

This work investigated the role of sucrose and cationic dispersant (1‐hexadecyl)trimethylammonium bromide concentration on ice‐templated sintered lithium titanate microstructure and compressive strength, to enable a comprehensive understanding of composition selection and elucidate processing–microstructure–mechanical property relationships. Sucrose and dispersant concentrations were varied to change total solute concentration in suspensions and viscosity. Dispersant was more effective in reducing viscosity than sucrose; however, their combination had an even greater impact on reducing viscosity. Based on viscosity measurements, a total of 12 suspension compositions were developed, and materials were fabricated at two different freezing front velocity (FFV) regimes. Solute concentration greatly influenced ice‐templated microstructure …

A Review On Heat Flux Measurement Techniques In The Nano And Microscale, Miguel Moreno

Honors Program: Senior Projects (Public)

Heat Flux measurements represent an important step in obtaining an accurate heat transfer profile in many engineering problems. Sensors capable of measuring this quantity have been around for decades, however, the increasing focus in nano and microscale applications in the industry and academia demands more accurate and smaller devices. This paper reviews some of the methods used to develop heat flux meters targeted to nano and microscale, as well as some calibration processes for the same. A combination of Luminescence and non-luminescence methods for direct and indirect measurement of heat flux will be discussed. A glimpse of what the future …

Nebraska Summary: 1231 John Deere 6r 120 Diesel Infinitely Variable Transmission, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Simulation Of Residual Stress Generation In Additive Manufacturing Of Complex Lattice Geometries, Katie Sue Bruggeman

Browse all Theses and Dissertations

Residual stresses developed during additive manufacturing (AM) can influence the mechanical performance of structural components in their intended applications. In this study, thermomechanical residual stress simulations of the laser powder bed fusion (LPBF) process are conducted for both simplified (plate and cube-shaped) geometries as well as five complex lattice geometries fabricated with Inconel 718. These simulations are conducted with the commercial software package Simufact Additive©, which uses a non-linear finite element analysis and layer-by-layer averaging approach in determining residual stresses. To verify the efficacy of the Simufact Additive© simulations, numerical results for the plate and cube-shape geometries are analyzed for …

Hypersonic Conceptual Design Tool Comparison, James G. Wnek

Browse all Theses and Dissertations

The many iterations needed to explore a design space in the conceptual design process preclude the use of time-consuming RANS CFD for all but a few flight conditions. This research focuses on identifying the level of fidelity needed to adequately predict the aerothermodynamic characteristics of hypersonic vehicles. Three tools with differing levels of fidelity – CBAERO, Cart3D, and Kestrel – were used to analyze the Generic Hypersonic Vehicle (GHV) at the design condition of Mach 5.85 and an off-design condition of Mach 4.5. The results are representative of the different design tools but are not definitive due to the mesh …

Vibration Bending Fatigue Analysis Of Additively Repaired Ti-6al-4v Airfoil Blades, Lucas Jordan Smith

Browse all Theses and Dissertations

Repairing airfoil blades is necessary to extend the life of turbine engines. Directed energy deposition (DED) additive manufacturing (AM) provides the ability to add material at a specific location on an existing component. In this work, AM repairs on Ti-6Al-4V airfoil blades were analyzed to determine what effect the repair will have on the blade performance in high cycle vibration fatigue testing. Targeted sections were cut out of airfoil blades near high stress locations and repaired using DED. To understand the defects that arose with this type of repair, computed tomography imaging was used to quantify the defects from the …

Editorial For The Special Issue On Micromachines For Non-Newtonian Microfluidics, Lanju Mei, Shizhi Qian

Mechanical & Aerospace Engineering Faculty Publications

In lieu of an abstract, this is an excerpt from the first page.

Microfluidics has seen a remarkable growth over the past few decades, with its extensive applications in engineering, medicine, biology, chemistry, etc [...]

Spray Deposition Of Sustainable Plant Based Graphene In Thermosetting Carbon Fiber Laminates For Mechanical, Thermal, And Electrical Properties, Daniel W. Mulqueen, Siavash Sattar, Thienan Le, Oleksandr G. Kravchenko

Mechanical & Aerospace Engineering Faculty Publications

Graphene has generated substantial interest as a filler due to its exceptional strength, flexibility, and conductivity but faces obstacles in supply and implementation. A renewable, plant-based graphene nanoparticle (pGNP) presents a more accessible filler with the same properties as mineral graphenes. In this study, we examine the effects of pGNP, which was sprayed on a carbon fiber/epoxy prepreg at loadings from 1.1 to 4.2 g/m². The study considered the mechanical, thermal, and electrical properties of pGNP-composite. An even particle dispersion was achieved using a spray application of pGNP in a water/alcohol suspension with the addition of surfactants and …

Human Ergonomic Simulation To Support The Design Of An Exoskeleton For Lashing/De-Lashing Operations Of Containers Cargo, Francesco Longo, Antonio Padovano, Vittorio Solina, Virginia D' Augusta, Stefan Venzl, Roberto Calbi, Michele Bartuni, Ornella Anastasi, Rafael Diaz

VMASC Publications

Lashing and de-lashing operations of containers cargo on board containerships are considered as quite strenuous activities in which operators are required to work continuously over a 6 or 8 hours shift with very limited break. This is mostly because containerships need to leave the port as soon as possible and containers loading and unloading operations must be executed with very high productivity (stay moored in a port is a totally unproductive time for a ship and a loss-making business for a shipping company). Operators performing lashing and de-lashing operations are subjected to intense ergonomic stress and uncomfortable working postures. To …

Satellite Drag Coefficient Modeling For Thermosphere Science And Mission Operations, Piyush M. Mehta, Smriti N. Paul, Nicholas H. Crisp, Philip L. Sheridan, Christian Siemes, Günther March, Sean Bruinsma

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Satellite drag modeling remains the largest source of uncertainty affecting space operations in low Earth orbit. The uncertainty stems from inaccurate models for mass density and drag coefficient. Drag coefficient modeling also impacts scientific knowledge on the physics and dynamics of the upper atmosphere through the estimation of high-fidelity mass density from measurements of acceleration on-board satellites. Efforts over the last decade have pushed drag coefficient modeling in the right direction, however, have resulted in multiple methods and tools. We provide a comprehensive review of the drag coefficient modeling methods and tools. Current scale differences between thermospheric data sets mostly …

Effects Of Wheel Rotation On Long-Period Wake Dynamics Of The Drivaer Fastback Model, Matthew Aultman, Rodrigo Auza-Gutierrez, Kevin Disotell, Lian Duan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Lattice Boltzmann method (LBM) simulations were performed to capture the long-period dynamics within the wake of a realistic DrivAer fastback model with stationary and rotating wheels. The simulations showed that the wake developed as a low-pressure torus regardless of whether the wheels were rotating. This torus shrank in size on the base in the case of rotating wheels, leading to a reduction in the low-pressure footprint on the base, and consequently a 7% decrease in the total vehicle drag in comparison to the stationary wheels case. Furthermore, the lateral vortex shedding experienced a long-period switching associated with the bi-stability in …

Schaeffler F-250 Bev Conversion: Power Electronics, Leslie Sawyer

Williams Honors College, Honors Research Projects

This report shows the work that was done on the power electronics system in the industry sponsored Schaeffler demonstration truck project. The goal of the project was to convert a combustion Ford F250 into a battery electric vehicle, while using as much Schaeffler technology as possible. After the vehicle is converted it will be used as a demonstration vehicle to show potential investors. While this project is still in progress, the work that was done during this time was substantial to the development of this project. Progress that has been made on the power electronics system includes developments in selecting …

Quickcut Waterjet Cutter, Kennedy Dunn, Jacob Storrow, Benjamin Laughrey

Williams Honors College, Honors Research Projects

The QuickCut Waterjet Cutter was created in 2019 as a senior design project. This is the third iteration of the waterjet cutter. The goal of this project was to create an operable CNC waterjet cutter that is able to cut 1/16” tensile specimens consisting of nonferrous metal or plastic. This machine will be utilized in the Manufacturing Laboratory at the University of Akron to provide education to interested students on the waterjet cutting process, how it operates, and industrial application of the technology. Waterjet cutting is a subtractive manufacturing process which is recognized for its specialized applications such as cutting …

Ballistic Impact Mitigation Pad, Adam Pianalto, Nathan Mayer, Wyatt Smith, Nick Green, Douglas Wild

Williams Honors College, Honors Research Projects

In our senior design project we have decided to work under Dr. Jon Gerhardt on creating a gel pad to mitigate blunt force behind bulletproof vests. Extensive research on injury, materials, manufacturing methods, and NIJ standards was completed during this project. Through the use of advanced modeling software and additive manufacturing, we prototyped a functioning pad to test and compare to a pad that is currently available in today's market. The results proved to be very successful, but there are many areas to improve upon down the road.

Dupont Seal Mold Assembly Machine, Brett Biederman, Craig Hanchett, Matthew Chilton

Williams Honors College, Honors Research Projects

The Seal Assembly Machine is a custom-built device that is designed to seat a thin polymer part between two mating pieces of metal tooling. To meet the specifications of the sponsor, the Seal Assembly machine must perform its function more quickly and accurately than manual labor at the same task. At the time of compiling this report, the machine is not yet functional due to time constraints.

Energy Analysis Of Heating, Ventilation, And Air Conditioning Systems, Erica Ferguson

Williams Honors College, Honors Research Projects

This project studied Heating, Ventilation, and Air Conditioning (HVAC) systems for commercial buildings. I completed an energy model Raleigh County Sheriff’s Department in West Virginia. This building’s HVAC has been completed by the consulting engineering firm: Scheeser Buckley Mayfield. I intern at this company, so they allowed me to use their original design as a basis for comparison. Load calculations, utility costs, energy consumption, and carbon footprint were derived from this energy analysis. The energy model compared three systems: variable air volume (VAV) with electric reheat, variable air volume with hydronic reheat, and variable refrigerant volume (VRV). Based on the …

Sintering Of 3-D Printed Metals, Adam Shuppe, John Griffiths

Williams Honors College, Honors Research Projects

There is a 3-D printer which prints metals such as 17-4 PH. In this project, we will learn how to use the machine to print samples, create a sintering graph for the material, and compare the properties with materials sintered using the machine. We will try to get as close as possible to the properties of the samples sintered using the machine. There will be a lot of samples made and tested, and we will learn how to use a testing machine and all other testing equipment in the department.

Photogrammetry Booth, Chidubem Igweagu

Williams Honors College, Honors Research Projects

This is a research type project that involves design, build and simulation sponsored by a faculty member in the Mechanical Engineering department. The title of the proposed project is Photogrammetry_Booth. A photo booth to have pets immobilized by taking an attention needs to be designed and manufactured. 4-6 cameras need to be installed to take photos simultaneously to represent the front, sides, back and arbitrary sides of a pet. An Arduino board and tablet will be installed to control cameras and user interface. The booth is mainly built by T-slotted frames and many functional and decorative parts will be precisely …

Adjust-A-Ramp, Taylor Sharrits, Courtney Banks, Emily Beck, Jazmin Buenrostro

Williams Honors College, Honors Research Projects

Adjust-A-Ramp is a portable ramp designed to ensure the safety of consumers and prevention of damage to cars, specifically towards low profile cars. A low-profile vehicle includes any vehicle that has a clearance off the ground of 6.5 inches or less. Advantages of low-profile vehicles include improved handling, better braking, increased fuel efficiency, increased stability, and an overall luxury aesthetic. The reduced tire size increases grip on smooth surfaces with better wheel response, creating a fast, more efficient ride. The simple tire tread patterns and the stiff sidewalls allow for lower rolling resistance which increases fuel economy. The Adjust-A-Ramp can …

Zip Shoes, Derek Ford, Garret Freund

Williams Honors College, Honors Research Projects

For our honors project we intend to create a new urban mobility solution. They are called Zip Shoes; they will be a pair of shoes with built in propulsion. We plan to use our cumulative engineering knowledge to modify an existing pair of shoes such that they can safely propel the user on wheels. We hope to achieve this by adding an electric drive train and necessary structural components onto the shoes. We are pursuing this project because we have seen the popularity of other electronically driven personal transportation devices. These include the hover board, electric skateboards, and electric scooters. …

Human Powered Vehicle Team Challenge, Sydney Nedlik, Spencer Brodie, Maria Griffin, William Schell, Ryan Serraglio

Williams Honors College, Honors Research Projects

Design and build a Human Powered Vehicle in a team of five. Compete at the ASME HPVC competition in March of 2022. Re-establish the Human Powered Vehicle Team at the University of Akron.

Recycled Printer Filament, Charlotte Hyland, Troy D. Molinar

Williams Honors College, Honors Research Projects

The purpose of this research is to examine the effects of recycling PLA filament for 3D printing on its material properties. After examining these effects, PLA and carbon fiber additives were mixed with recycled PLA pellets in different ratios to attempt to regain material properties lost in the recycling process. To complete these findings, an experiment was design and executed.

The research found that tensile strength during multiple iterations of recycling remained mostly unaffected, however, the strain degraded exponentially. In the PLA additive study, high ratios of PLA additive were able to increase the strength and strain properties of the …

Integrating Wave-Powered Batch Reverse Osmosis With Pressure Retarded Osmosis For Higher Efficiency Desalination Method, David M. Warsinger, Akshay Rao, Abhimanyu Das, Sultan Alnajdi, Ali Naderi, Antonio Esquivel, Alondra Ramos, Cole Heald, Vivek Singh, Ryan Soltis, Kaitlyn Kelsey, Adriana Hisham, Aaron Harp, Bryan Pamintuan, Paige Beck, Matthew Sheridan, John Pacholski, Carolina Bernal Botero

School of Mechanical Engineering Faculty Publications

Overpopulation, intensive industrial water usage and climate change are some of the occurrences that are exacerbating global water scarcity. By 2050, the United Nations predicts that over 6 billion people will be affected by water scarcity. Over 70% of the earth's surface is covered by oceans yet its water remains unusable due to the high salinity of seawater. Reverse Osmosis (RO) is the most common method of desalinating water but is dependent on non-renewable generated electricity to meet its high energy requirements. The majority of the power supplied to desalination plants is generated using emission-heavy fuels. Given the UN’s goal …

Refrigeration & Pressure Circuits For The Test Apparatus On Triaxial Properties Of Polymer Foams At Arctic Temperatures, Nathaniel Ackerman

Williams Honors College, Honors Research Projects

The objective of this project is to modify the previous testing apparatus used by Dr. M. Hoo Fatt for exploration of Crushing Behavior of Polymer Foams in Sandwich Structures Operating in Arctic Regions commissioned by the Office of Naval Research and performed under the University of Akron’s Mechanical Engineering testing facilities. To do this, it is required to design a system capable of operating at a constant temperature during a testing cycle, reaching down to -60⁰C. This apparatus must also be compatible with prior equipment, facilities, persons, samples, and media.

Primarily, a copper-tube refrigeration coil design was considered to lead …

Laser-Assisted Sound Source Localization Inside A Solid Enclosure, Antonio Figueroa Mombela

Wayne State University Dissertations

Sound source localization is typically conducted in open space so that the line of sight is not blocked among individual sensors. This research presents a new technology that enables one to see acoustically through a solid Plexiglass enclosure to locate a sound source stationed inside at some arbitrarily selected locations. By using SODAR technology, non-invasive laser-assisted microphones, analog, and digital signal processing (band-pass filtering, fast Fourier transform algorithm, cross-correlations, and triangulations) satisfactory sound source localization results were obtained. In this project, the enclosure walls were flat; only the azimuth angle of a sound source could be determined. To obtain the …

A Combined Additive - Deformation - Machining (Adm) Manufacturing Process With Controlled Microstructures, Ahmed Nabil Taher Elalem

Wayne State University Dissertations

ABSTRACTA COMBINED ADDITIVE - DEFORMATION - MACHINING (ADM) MANUFACTURING PROCESS WITH CONTROLLED MICROSTRUCTURES by AHMED NABIL TAHER ELALEM August 2022

Advisor: Dr. Xin WuMajor: Mechanical Engineering Degree: Doctor of Philosophy

Direct metal additive manufacturing provides great flexibility in 3D shaping compared to traditional manufacturing processes of metal casting, deformation followed by machining and joining for obtaining the final production shape. On the other hand, it suffered from its dendric microstructure produced during solidification. This study reports the development of new combined metal additive and deformation processes to take advantage and reduce/eliminate the drawback of individual processes. The heating source mainly …