Mechanical Engineering Commons^™

A Modified Wilshire Model For Creep Deformation And Damage Prediction, Jaime Aaron Cano

Open Access Theses & Dissertations

In this work, a new constitutive model, the WCS model, is derived that combines the Wilshire equations with continuum damage mechanics (CDM) for the long-term prediction of creep deformation, damage, and rupture. Long-term creep data is expensive and time-consuming to obtain because conventional creep testing is real-time. There is a need to extrapolate long-term creep behaviors from short-term data. Models that can accurately predict long-term creep behavior over a wide range of boundary conditions are vital for design engineers. The classic Wilshire equations can accurately extrapolate the long-term stress-rupture, minimum-creep-strain-rate, and time-to-strain of various alloys as their functional form has …

Development Of An Ionic Green Monopropellant 1 Newton Thruster For Small Satellite Application, Jaclyn Mona Mejia

Open Access Theses & Dissertations

In effort to advance green monopropellant propulsion using AF-M315E, a 1N thruster was developed to demonstrate the propellant capabilities for low thrust requirement missions. The current study presents the development of a 1 Newton thruster. The thruster was designed based on available literature for initial parameters. In house developed catalyst was packed into the 1 Newton thruster, and mounted onto a thrust stand for testing. Two configurations of catalyst were used for this testing campaign. As a result, temperature peaks from AF-M315E decomposition gases reached up to 1400°C with an iridium loading factor of 25% by mass with both catalyst …

Direct Write 3d Printing Of Functional Ceramics, Jorge Angel Diaz

Open Access Theses & Dissertations

Humidity sensors are used in many industries and are important for ensuring quality and safety. Ceramic sensors are preferred because of their quick response time, ability to withstand high temperatures and excellent Chemical and mechanical stability. The manufacturing world has been moving toward additive manufacturing which is a form of synthesizing 3D tangible layer by layer in witch minimal waste is produced. Additive manufacturing also is known as 3D printing has opened new possibilities to design engineers by giving them design freedom and access to the layers of a part to allow embedded sensors. There is a category of ceramics …

Computational Study Of Flow Interactions Over A Close Coupled Canard-Wing On Fighter, Setyawan Bekti Wibowo, Sutrisno Sutrisno, Tri Agung Rohmat

International Journal of Aviation, Aeronautics, and Aerospace

There have been many attempts to improve the flying performance of a fighter. By modifying the flow that occurs along the fuselage is expected to improve the performance of the aircraft. One of the indicators of combat aircraft performance is the ability to perform maneuver movement. Adding a canard as forewing on the fighter wing configuration is considered capable of raising the ability in maneuver movement. The use of canard-delta pairs will affect the performance and aerodynamic characteristics of the plane. Wings and canards with delta configuration will make the rolled-up vortex as a lifting force producer on the aircraft. …

Reactive Archey Target Design Team "Mimic", Brandon Croyle, Jacob Boss, David Rodgers, Austin Wivell

Williams Honors College, Honors Research Projects

This design project will aim to provide archery hunters with a platform to simulate shooting at string jumping deer. String jumping refers to a spooked deer hearing the snap of a bow string and instintivly ducking up to ten inches. This often results in wounded or missed deer. We will design and build a control system that uses the sound of a bow string as a trigger to operate a mechanical target system. A sound sensor will mimic a deer’s hearing in close range hunting and then send a signal to the mechanical system to replicate the dropping motion of …

Center Lift Trailer Support Structure, Carson Corle, Anthony M. Hayes, Bryan A. Truax

Williams Honors College, Honors Research Projects

Center lift pontoon trailers have a high center of gravity, therefore have the potential for the pontoon and trailer to tip while cornering. There is need for a component to stabilize the pontoon on the trailer while towing. Different concepts of a support system were sketched to determine the best option. The characteristics that were deemed important for the support system were narrowed down to determine the best concept and the connections of the best design were sketched in greater detail. The forces that the support system would have to withstand to stabilize the pontoon on the trailer were calculated. …

Interlaminar Damage Detection In Composite Materials, Hariharan Rangarajan

Williams Honors College, Honors Research Projects

Using ceramic matrix composites (CMCs) for high-temperature applications in jet engines increases durability and reduces weight and cooling requirements resulting in improved efficiency and fuel savings. Understanding, detecting, and monitoring different types of damage is essential to achieve optimal performance of CMC components. The Direct Current Potential Drop (DCPD) method is a non-destructive technique of estimating damage in composite materials.

DCPD technique works by measuring nodal potential differences when current is flown through the material. Direct current spreading in different woven and laminate composites is modeled to follow a ladder resistor network in which the nodal voltages decrease exponentially as …

Metric Coil Car, Abigail Eberly

Williams Honors College, Honors Research Projects

Coil cars are a vital part of many steel mills. They allow mills to easily transfer a coil from one location to another without the use of a crane, manual labor, or other extraneous forces. Steel Equipment Specialists, or SES, gets multiple orders every year for coil cars. While the general functions and goals of the cars remains consistent, the details, such as the size of the car, the distance between rails, and the weight/ size of the coils differs between each place. Due to this variety, SES has requested a coil car that can easily be manipulated and produced …

Carbon Fiber Monocoque, Dan Brown, Leland Hoffman

Williams Honors College, Honors Research Projects

The University of Akron’s Human Powered Vehicle Team designed a high performing, fully functioning vehicle that is safe, efficient, and practical for the 2018-2019 season. These objectives were the main priorities when it came to the initial stages of designing the vehicle. In addition, the vehicle was designed in accordance with the ASME 2019 Human Powered Vehicle Challenge guidelines to satisfy all the rules and requirements. Additional priorities have been created to teach practical engineering skills and techniques to the students participating in the project through different points in the production process including research, vehicle design, construction, and testing.

The …

Multiphase Droplet Interactions With A Single Fiber, Noor M. Farhan

Theses and Dissertations

Abstract

Multiphase Droplet Interactions with a Single Fiber

By: Noor M. Farhan

A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at Virginia Commonwealth University.

Virginia Commonwealth University, 2019

Director: Hooman V. Tafreshi,

Professor, Department of Mechanical and Nuclear Engineering

Formulating the physics of droplet adhesion to a fiber is interesting intellectually and important industrially. A typical example of a droplet–fiber system in nature is the dew droplets on spider webs, where droplets first precipitate and grow on the fibers, but they eventually fall when they become too heavy. Obviously, quantifying the force …

Modeling Electrospun Fibrous Materials, Sina Hassanpouryousefi

Theses and Dissertations

Electrospinning has been the focus of countless studies for the past decades for applications, including but not limited to, filtration, tissue engineering, and catalysis. Electrospinning is a one-step process for producing nano- and/or micro-fibrous materials with diameters ranging typically from 50 to 5000 nm. The simulation algorithm presented here is based on a novel mass-spring-damper (MSD) approach devised to incorporate the mechanical properties of the fibers in predicting the formation and morphology of the electrospun fibers as they travel from the needle toward the collector, and as they deposit on the substrate. This work is the first to develop a …

Calculation Methods Of Radon-222 Radiological Activity For Norm Plant With Ventilation, Pedro M. Dieguez-Elizondo, Paul G. O'Donohoe, Tomas Gil-Lopez, Juan Castejon-Navas, Miguel A. Gálvez-Huerta

Articles

A procedure is proposed to determine the radiological activity of air present in the working area of a NORM (Naturally-Occurring Radioactive Materials) plant. This NORM plant is located in the United Arab Emirates and is dedicated to the recycling of material and equipment used in oil extraction facilities. Substantial quantities of NORM waste will be present inside the enclosed plant facilities and will exhale significant amounts of Radon-222 into the working environment. The continued inhalation of this gas and its progeny has been shown to cause lung cancer. In order to reduce the concentration level of the aforementioned gas to …

Economic Appraisal Of Hybrid Solar-Biomass Thermophotovoltaic Power Generation, Cm Iftekhar Hussain, Aidan Duffy, Brian Norton

Conference Papers

The techno-economic parameters that influence the commercial deployment of hybrid thermophotovoltaic (TPV) solar power generation are determined using annual system simulations. It has been found that a TPV cell price of E5/cm2 or less together with a TPV operating temperature under 800°C is required for a hybrid solar–biomass TPV power plant to be economically competitive with the state-of-the-art hybrid solar–biomass Rankine cycle power plants.

Solar Tracker Renewable Energy, Stephanie Christie, Annabeth Helmly, Matthew Smith, Katrina Vaughan

ENgaging Educators in Renewable enerGY (ENERGY): Lesson Plans & Slideshows (2017-2019)

No abstract provided.

Analysis Of Horizontal Axis Wind Turbine Array Optimization, Peter-Claver Nwanze, Keith Bazemore, Jessica Lyons, J. Ann Mitchem

ENgaging Educators in Renewable enerGY (ENERGY): Lesson Plans & Slideshows (2017-2019)

Wind energy is the fastest growing form of renewable energy, with a multitude of possibilities for expansion. This, as well as other forms of renewable energy, will facilitate understanding of the growing concerns regarding global warming by decreasing our dependence on fossil fuels. Wind energy requires wind speeds of at least six miles per hour; therefore, only certain geographical areas are suitable for the use of this technology. The purpose of this experiment was to determine whether the orientation of an array of wind turbines increases or decreases energy production and efficiency. In this study, various arrays consisting of five …

Energy Lesson Design, Jessica Lyons

ENgaging Educators in Renewable enerGY (ENERGY): Lesson Plans & Slideshows (2017-2019)

No abstract provided.

Pico-Grid Smart Homes Power Management System, Kathleen Hobbs, Mbonya Myers

ENgaging Educators in Renewable enerGY (ENERGY): Lesson Plans & Slideshows (2017-2019)

No abstract provided.

Resonant Acoustic Wave Assisted Spin-Transfer-Torque Switching Of Nanomagnets, Austin R. Roe

Theses and Dissertations

We studied the possibility of achieving an order of magnitude reduction in the energy dissipation needed to write bits in perpendicular magnetic tunnel junctions (p-MTJs) by simulating the magnetization dynamics under a combination of resonant surface acoustic waves (r-SAW) and spin-transfer-torque (STT). The magnetization dynamics were simulated using the Landau-Lifshitz-Gilbert equation under macrospin assumption with the inclusion of thermal noise. We studied such r-SAW assisted STT switching of nanomagnets for both in-plane elliptical and circular perpendicular magnetic anisotropy (PMA) nanomagnets and show that while thermal noise affects switching probability in in-plane nanomagnets, the PMA nanomagnets are relatively robust to the …

The Educational Value Of Modelling Complex Thermodynamic Systems With System Dynamics Software, Stephen Crown, Constantine Tarawneh

Mechanical Engineering Faculty Publications

The solution of problems involving complex thermodynamic systems often occupies much of a students' time and can be a distraction from them developing a clear understanding of system components, interaction of subsystems, modelling simplifications and assumptions, and design optimization. Refocusing students on the fundamental concepts of thermal systems design and analysis is possible with the introduction of system modelling software that carries some of the load of repetitive calculation required for complex systems. Models of thermodynamic systems encountered in an advanced undergraduate thermodynamics course were developed by students (some provided to students) to solve homework problems of complex steam power …

Rheological Properties Of Two Stainless Steel 316l Powders For Additive Manufacturing, Haijun Gong, Xiaodong Xing, Hengfeng Gu

Manufacturing Engineering: Faculty Publications (2015-2023)

This study measures the rheological properties of two stainless steel 316L powders which are used for the powder-bed-fusion based additive manufacturing process. The purpose is to evaluate the newly acquired powder in comparison with the used and recycled powder, so that both powders can be mixed with each other to supplement the powder usage. The powder rheology properties, such as dynamic property, bulk property, and shear property, are tested and compared. The results and analysis confirm the compatibility of powder mixing.

Determine Airborne Release Fractions (Arf) / Respirable Fractions (Rf) For Use In Safety Based Documents, Michael Quinn, Jacob Miller

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.

What Is A Bim Design Model?, James Peters, Malachy Mathews

Conference papers

The recent report into Building Information Management or BIM, by construction law experts May Winfield and Sarah Rock entitled “Winfield Rock Report” [1] gives reason to state that the UK architectural, engineering and construction industry or AEC, is hindered by the absence of a clear definition of Level 2 BIM. The ISO 19650-2 standard published in 2019, is based upon PAS1192-2:2013. The intent of ISO 19650-2 is to provide a road map to facilitate the standardisation of BIM process in a uniformed fashion. A key pillar of ISO 19650 is the “information cycle” and central to this is a federated …

A Framework For Energy Optimization Of Small, Two-Stroke, Natural Gas Engines For Combined Heat And Power Applications, Mahdi Darzi

Graduate Theses, Dissertations, and Problem Reports (ETD)

This research was focused on the development of a framework for the energy optimization a natural gas engine for small combined heat and power (CHP) applications operating with low-pressure natural gas (NG) available at homes. The required targets of the ARPA-E GENSETS program for 1 kW electric power generation and previous GENSETS simulation at West Virginia University, suggested a design space for the engine which is currently dominated by simple two-stroke designs. Hence this research focused on screening, modeling, and experimentally evaluation of cost-effective technologies to achieve a system design that maximized thermal efficiency and utilization factor, while reducing emissions. …

Modeling And Development Of The Dynamic Environmental Simulation Chamber (Desc) For Calibration Of Air Quality Monitoring Sensors, Filiz Kazan

Graduate Theses, Dissertations, and Problem Reports (ETD)

The thesis describes the development steps for the dynamic environmental simulation chamber (DESC) and carbon dioxide sensor calibration by using DESC. The sensors are Figaro, COZIR and K30 CO2 sensors

Design Of Experiment And Analysis Techniques For Fuel Consumption Data Using Heavy-Duty Diesel Vehicles And On-Road Testing, Sarah Ann Mills

Graduate Theses, Dissertations, and Problem Reports (ETD)

Chassis dynamometer and on-road testing are usually employed to test vehicle operation. Testing on a chassis dynamometer reduces data variability compared to on-road testing due to the controlled environment but it does not account for other important variables that affects real-world vehicle operation. This study used on-road testing to investigate the differences between two test fuels under real-world conditions. Three heavy-duty diesel vehicles were driven on different routes for a period of three months. Each vehicle was instrumented with flow meters to gather fuel consumption data, which was then compared to the fuel rate broadcasted by the engine control unit …

Aerosol-Jet Printing And Flash Sintering Of Conformal Conductors On Non-Planar Surfaces, I-Meng Chen

Masters Theses

”The printed electronics have been broadly applied in our daily lives, many new manufacturing methodologies are studied and investigated. The research here presented the full manufacturing process of printed conductors of aerosol printing and flash sintering techniques on substrates such as planar and non-planar surfaces.

The aerosol printing (AJP) was introduced because of its simplicity in experimental setup and flexibility of printing. It produces less ink waste and consumes less manufacturing cost. Furthermore, it has the direct-write ability to print in any customized patterns or shapes on non-planar surfaces. In this study, the Cu NPs was selected as the functioning …

A Review Of 3d Gis For Use In Creating Virtual Historic Dublin, Alain Chenaux, Maurice Murphy, S. Pavia, S. Fai, T. Molnar, John Cahill, Shane Lenihan, A. Corns

Conference papers

This paper illustrates how BIM integration with GIS is approached as part of the workflow in creating Virtual Historic Dublin. A design for a WEB based interactive 3D model of historic buildings and centres in Dublin City (Virtual Historic Dublin City) paralleling smart city initiates is now under construction and led by the National Monuments at the Office of Public Works in Ireland. The aim is to facilitate the conservation and maintenance of historic infrastructure and fabric and the dissemination of knowledge for education and cultural tourism using an extensive Historic Building Information Model. Remote sensing data is now processed …

Comparison Of Drag Area Estimation Using Natural Coast Down And Constant Speed Test Methods, Cem Baki Mr

Graduate Theses, Dissertations, and Problem Reports (ETD)

Currently in US, more than 26 percent of the total GHG emissions comes from transportation and mostly from heavy duty vehicles. Similarly, the European Council stated that 25 percent of the emissions comes from heavy duty transportation and they expect it to be further increased in the future. However, with the new coming regulations US EPA and European Council aiming to reduce the emissions by 80 percent in US and 60 percent in EU. In order to keep track and control the emissions, both authorities published new regulations and testing methods for certifying the new vehicles.

Aerodynamic testing is one …

Surf Zone Tilt Current Meter, Troy Heitmann

Link Foundation Ocean Engineering and Instrumentation Fellowship Reports

Coastal tides and free surface gravity waves locally interact with the nearshore bathymetry generating spatially diverse circulation cells. Collectively, the cells form a current velocity flow field where net transport of geological, chemical, or biological, particulates takes place. Within the surf zone, dynamic instabilities lead to chaotic evolution and mixing, where single point, observations fail to quantitatively char­acterize the system as a whole. Governed by advanced theories, numerical models provide the necessary sampling resolution to study surf zone processes over large do­mains, but the model must be validated with field observations to draw meaningful conclusions. The acoustic Doppler current profiler …

Link Foundation Fellowship Report, Eric Nieves

Link Foundation Ocean Engineering and Instrumentation Fellowship Reports

Magnetic anomaly detection (MAD) is a leading technique for the detection and localization of obscured magnetic targets via exploiting the field anomalies they create. This is especially true in marine environments when looking for unexploded ordnance (UXO), because the DC magnetic field is not highly influenced by numerous types of media (i.e. water) or weather conditions. MAD is also a passive technique, which allows it to go unnoticed by the target. Whereas current applications of MAD have been shown to be effective for localizing single targets at a time, the development of a method for multiple localization would the robustness …