Engineering Commons^™

Modeling Radionuclide Diffusion Using Moose A Multiscale, Multiphysics Platform, Jonathon Gardner

Theses and Dissertations

Very durable ceramic waste forms have been proposed which offer longterm stability by binding certain radionuclides in their specific crystalline network. Moreover, multiple such ceramic phases can be tailored to contain specific radionuclides generated in the fuel cycle. Many such candidate ceramic forms are in the early stages of development with limited data. Modeling and simulation including modeling of diffusion can inform and provide direction to ongoing fabrication and experimental efforts. Material properties important in modeling can be obtained through laboratory measurement where available and atomistic simulation. Since diffusion occurs over multiple scales and follows multiple pathways, multiscale modeling is …

Anisotropic Electrical Response Of Carbon Fiber Reinforced Composite Materials, Mohammad Faisal Haider

Theses and Dissertations

Composites materials are often subjected to multi-physical conditions in different applications where, in addition to mechanical loads, they also need to sustain other types of loads such as electrical currents. The multi-physical behavior of composites needs to be understood and analyzed to facilitate new multi-functional material design. An essential first step towards this goal is to understand how multi-physics properties depend on local details (e.g. micro-structure). Composite materials have heterogeneous electrical properties (carbon/epoxy) at the local level that can be different at the global level. To conduct the multi-physics study, the electrical signal is employed to the composite sample for …

Knee Internal Forces In Moderate Squat Exercise, Dumitru I. Caruntu, Jose Mario Salinas

Mechanical Engineering Faculty Publications and Presentations

This paper deals with internal forces of human knee during moderate squat exercise. The moderate squat exercise consists of a descending phase from standing to the lowest position (largest flexion angle) in which no significant contact between thigh and calf occurs, and an ascending phase back to standing position. This research predicts the internal forces such as muscle forces, contact forces, and ligamentous forces. The ligamentous structures in this research consist of Anterior Cruciate Ligament (ACL), Posterior Cruciate Ligament (PCL), Lateral Collateral Ligament (LCL), and Medial Collateral Ligament (MCL). The ligaments are modeled as nonlinear elastic strips (they do not …

Production Of Β-Silicon Carbide Nanofibers Using The Forcespinning® Method, Alfonso Salinas, Aleksey Altecor, Maricela Lizcano, Karen Lozano

Mechanical Engineering Faculty Publications and Presentations

Silicon carbide (SiC) nanofibers were produced on a large scale using the Forcespinning® method. Non-oxide ceramics such as SiC are known for their low density, oxidation resistance, thermal stability, and wear resistance. The nanofibers were prepared using a solution-based method with polystyrene and polycarbomethylsilane as the precursor materials. Fiber spinning was performed under different parameters to obtain high yield, fiber homogeneity, and small diameters. The fibers were spun under a controlled nitrogen environment to prevent fiber oxidation. The resultant nonwoven nanofiber mats were then subjected to different heat treatments to evaluate the effect of these on the crystalline structure. Characterization …

Optimization Of Formula Sae Electric Vehicle Frame With Finite Element Analysis, Alexander Prorok

Williams Honors College, Honors Research Projects

Optimization of Formula SAE Electric Vehicle Frame with Finite Element Analysis

The University Of Akron Nfpa 2015/2016 Chainless Challenge, Andrew Tupta, Andrew Ball, Stefan Stamboldziev, Jordon Spence, Sean Catchpole

Williams Honors College, Honors Research Projects

Parker Hannifin has issued a challenge to student design teams of creating a Chainless bike using a hydraulic system. Each student design team will be assigned a technical advisor from the University. The project will be divided into two phases after the initial kickoff. The first phase will align with senior design course for motion control and hydraulics and will yield the student obtaining knowledge in hydraulics, including bio-degradable fluids, pneumatics, electromechanical systems, green technologies (sustainable energy) and controlling force and motion. Students will be provided data sheets, a list of in-stock Parker components and by the end of the …

Corrosion Protection Systems In Offshore Structures, Hristo Ivanov

Williams Honors College, Honors Research Projects

Corrosion plays a pivotal role in the engineering world. Engineers of all disciplines must consider the dangers that this phenomenon can incur. Interestingly, corrosion mitigation is not a topic that is addressed in most academic curricula. The goal of this paper is to give engineering students a brief introduction into corrosion and some of the prevention techniques commonly used today.

The design of a corrosion protection system for offshore structures is discussed in order to illustrate how these techniques can be utilized even in the most extreme environments. First, the driving force behind corrosion is examined, introducing the basic mechanics …

Finite Element And Probabilistic Analysis Of Soft Tissue Structures Of The Human Lumbar Spine, Dana Joseph Coombs

Electronic Theses and Dissertations

Human lumbar spine mechanics are influenced by soft tissue structures. Understanding and properly modeling these structures can help determine pathology, treatment, and implant design and performance. Finite element models of the L4-L5 level of the lumbar spine are often used, which include a representation of the intervertebral disc and spinal ligaments. Validation of these models are typically based on torque rotation data from a single subject or the models use average properties reported in literature. However, experimental testing reports variation up to 40% in ligament stiffness and even greater variability for annulus fibrosis properties. Probabilistic approaches enable consideration of the …

Regression Analysis Of Pem Fuel Cell Transient Response, Russell L. Edwards, Ayodeji Demuren

Mechanical & Aerospace Engineering Faculty Publications

To develop operating strategies in polymer electrolyte membrane (PEM) fuel cell-powered applications, precise computationally efficient models of the fuel cell stack voltage are required. Models are needed for all operating conditions, including transients. In this work, transient evolutions of voltage, in response to load changes, are modeled with a sum of three exponential decay functions. Amplitude factors are correlated to steady-state operating data (temperature, humidity, average current, resistance, and voltage). The obtained time constants reflect known processes of the membrane heat/water transport. These model parameters can form the basis for the prediction of voltage overshoot/undershoot used in computational-based control systems, …

Computational Assessment Of Neural Probe And Brain Tissue Interface Under Transient Motion, Michael Polanco, Sebastian Bawab, Hangsoon Yoon

Mechanical & Aerospace Engineering Faculty Publications

The functional longevity of a neural probe is dependent upon its ability to minimize injury risk during the insertion and recording period in vivo, which could be related to motion-related strain between the probe and surrounding tissue. A series of finite element analyses was conducted to study the extent of the strain induced within the brain in an area around a neural probe. This study focuses on the transient behavior of neural probe and brain tissue interface with a viscoelastic model. Different stages of the interface from initial insertion of neural probe to full bonding of the probe by astro-glial …

Electrokinetic Phenomena In Pencil Lead-Based Microfluidics, Yashar Bashirzadeh, Venkat Maruthamuthu, Shizhi Qian

Mechanical & Aerospace Engineering Faculty Publications

Fabrication of microchannels and associated electrodes to generate electrokinetic phenomena often involves costly materials and considerable effort. In this study, we used graphite pencil-leads as low cost, disposable 3D electrodes to investigate various electrokinetic phenomena in straight cylindrical microchannels, which were themselves fabricated by using a graphite rod as the microchannel mold. Individual pencil-leads were employed as the micro-electrodes arranged along the side walls of the microchannel. Efficient electrokinetic phenomena provided by the 3D electrodes, including alternating current electroosmosis (ACEO), induced-charge electroosmosis (ICEO), and dielectrophoresis (DEP), were demonstrated by the introduced pencil-lead based microfluidic devices. The electrokinetic phenomena were characterized …

Finite Element Modeling Of Active And Passive Behavior Of The Human Tibialis Anterior: A Preliminary Approach, David Joda

Dissertations, Master's Theses and Master's Reports

This research project serves as exploratory work in the field of computational human biomechanics. A connection between muscular force and intramuscular pressure (IMP) has been uncovered that could prove invaluable in medical diagnostics as a method to circumvent the use of electromyography.

Preliminary finite element simulations were conducted to model the human tibialis anterior muscle in passive lengthening and active contraction. These simulations, totaling over 50 unique runs, utilized a novel constitutive model developed within the IMP research group. Volumetric strain, reaction forces, and pressure gradients were compared to data acquired from ongoing in vivo human experiments. A mechanism for …

Design, Fabrication And Analysis Of An Auxiliary Power Unit On A Heavy-Duty Truck To Power The Hvac Systems Of The Truck During Driver Off-Duty Conditions, Rohan Milind Kalurkar

Dissertations, Master's Theses and Master's Reports

Currently, one of the biggest challenges the world is facing is energy insufficiency. One of the contributors to energy consumption in United States are the idling semi-trailer trucks. In May 2001, President Bush issued The National Energy Policy in which he directed The Environmental Protection Agency (EPA) and Department of Transportation (DOT) to reduce the idling of trucks. This was done in order to reduce energy consumption by lowering fuel consumption and emissions coming out of semi-trailer trucks in the United States of America.

This project deals with the efforts of installing an Auxiliary Power Unit (APU) as a device …

Mechanical Testing Of Fused Filament 3-D Printed Components For Distributed Manufacturing, Nagendra Gautam Tanikella

Dissertations, Master's Theses and Master's Reports

Fused filament fabrication (FFF)-based open-source 3-D printers offer the potential of decentralized manufacturing both in developing and developed countries. Unfortunately, a severe lack of data and standards relating to material properties and printed components limit this potential. This thesis first investigates the mechanical properties of a wide-range of FFF materials and provides a database of mechanical strength of the materials tested. The results demonstrate that the tensile strength of a 3-D printed specimen depends largely on the mass of the specimen, which provides a means to estimate the strength of 3-D printed components. Then this information is used to evaluate …

Finite Element Analysis And Topology Optimization Of Differential Case And Control Arm For Static And Fatigue Loading, Pankaj N. Kalan

Dissertations, Master's Theses and Master's Reports

Optimization of the automobile components can result in a significant decrease in vehicle weight, increase in fuel efficiency and reduction in environmental damage. For example, the lightweight vehicle production will save over 4.4×109 GJ of energy and 4.1×108 tons of CO2 over a 10 year period, compared to the current non-light weight vehicles. This equates to 890 billion miles or 42 billion gallons of gas savings (Wu 2016). This study evaluates the weight reduction possible by using manual and automatic (using Optistruct software) topology optimization processes. Optimization of a vehicle differential case done in this study shows that a weight …

Competition Vehicle Based Intake Manifold Design, Joshua N. Matiash

Dissertations, Master's Theses and Master's Reports

A competitive vehicle in Formula SAE needs to be easy for unskilled drivers to extract the maximum performance from. This requires a predictable and manageable torque curve. This report details the development of an intake manifold for a Formula SAE car from a vehicle-based approach to produce this manageable and predictable torque. The current vehicle was instrumented and driven on a representative track to determine the usage of available torque. Based on these findings an ideal torque curve was chosen that favored increased torque at upper engine speed ranges and decreased torque at lower engine speed ranges. A 1-D engine …

Design Of A Mobile Underwater Charging System, Brian R. Page

Dissertations, Master's Theses and Master's Reports

Autonomous Underwater Vehicles (AUVs) are extremely capable vehicles for numerous ocean related missions. AUVs are energy limited, resulting in short mission endurance on the scale of hours to days. Underwater Gliders (UGs) are able to operate on the order of months to years by using nontraditional propulsion methods. UGs, however, are unable to perform missions requiring high speed or direct forward motion due to the nature of their buoyancy driven motion. This work reviews the current state of the art in recharging AUVs and offers an underwater recharging network concept at a significantly reduced cost to traditional methods. The solution …

Hybrid Ant Colony Optimization For Fuzzy Unrelated Parallel Machine Scheduling Problems, Po An Su

LSU Master's Theses

This study extends the best hybrid ant colony optimization variant developed by Liao et al. (2014) for crisp unrelated parallel machine scheduling problems to solve fuzzy unrelated parallel machine scheduling problems in consideration of trapezoidal fuzzy processing times, trapezoidal fuzzy sequencing dependent setup times and trapezoidal fuzzy release times. The objective is to find the best schedule taking minimum fuzzy makespan in completing all jobs. In this study, fuzzy arithmetic is used to determine fuzzy completion times of jobs and defuzzification function is used to convert fuzzy numbers back to crisp numbers for ranking. Eight fuzzy ranking methods are tested …

On The Degradation Of Lubricating Grease, Asghar Rezasoltani

LSU Doctoral Dissertations

A comprehensive literature review on physical and chemical degradation monitoring and life estimation models for lubricating greases is presented in chapter one. Degradation mechanisms for lubricating grease are categorized and described, and an extensive survey of the available empirical and analytical grease life estimation models including degradation monitoring standards and methods are presented. In chapter two, irreversible thermodynamic theory is employed to study the mechanical degradation of lubricating grease. A correlation between the mechanical degradation and entropy generation is established and the results are verified experimentally using a rheometer, a journal bearing test rig, and a modified grease worker machine. …

Design Of Surface Texture For The Enhancement Of Tribological Performance, Cong Shen

LSU Doctoral Dissertations

Surface texturing is a method of surface modification that fabricates micro patterns on the contacting surfaces to improve the tribological performance in sliding, lubricated system. It is found that the geometric design of textures has a significant influence on the performance of textured surfaces. Some important geometric parameters, such as the area ratio and the depth-over-diameter ratio, have been identified for textures in the form of circular dimples. The current study aims to improve the friction reduction effect of surface texturing by using textures with novel designs. Some new factors considered in the design of textures are: internal structure and …

Thermophysical And Thermochemical Property Measurement And Prediction Of Liquid Metal Titanium Alloys With Applications In Additive Manufacturing, Jonathan Richard Raush

LSU Doctoral Dissertations

Accurate high-temperature thermophysical property data for liquid metals and alloys are important for simulation of laser-based 3D printing processes. To understand and better control such additive manufacturing processes, knowledge of density, viscosity, and surface tension of liquid metals and alloys versus composition and temperature is needed. Likewise, thermochemical property data information regarding alloys, including chemical activities and free energies relative to composition and temperature, aid in the understanding and development of phase data important in the material design process. Vacuum electrostatic levitation (ESL) is an important technique through which both thermophysical and thermochemical property measurements can be accomplished without physical …

Optimization-Based Path Planning For Separation Assurance On Small Unmanned Aircraft, Matthew Duffield, Andrew Ning, Timothy Mclain

Faculty Publications

This paper presents a time-based path planning optimizer for separation assurance for unmanned aircraft systems (UAS). Given Automatic Dependent Surveillance-Broadcast (ADS-B) as a sensor, intruder information such as position, velocity, and identification information is available at ranges on the order of 50 nautical miles. Such long-range intruder detection facilitates path planning for separation assurance, but also poses computational challenges. The time-based path optimizer presented in this paper provides a path-planning method that takes advantage of long-range ADS-B information and addresses the associated challenges. It is capable of long-range path planning and, due to the convex formulation, is computationally efficient enough …

Process Improvement By Lean Thinking In Trucking Industry, Abhiram Reddy Ramasahayam

All Graduate Theses, Dissertations, and Other Capstone Projects

Manufacturing industries with complex production systems are struggling with designing optimal process to increase throughput. Companies will require high amount of labor and process improvement resources to sustain growth and delivery quality products to its customers. A chain of value added activities when designed and deployed with help of lean based methodologies can create high efficiency process. In this paper we have studies and implemented value added process based on the lean manufacturing methodologies which was adapted on the shop floor.

In many traditional truck body production industries have facing many problems like low production rate, big lead times, material …

Magnetic Materials Characterization And Modeling For The Enhanced Design Of Magnetic Shielding Of Cryomodules In Particle Accelerators., Sanjay K. Sah

Theses and Dissertations

Particle accelerators produce beams of high-energy particles, which are used for both fundamental and applied scientific research and are critical to the development of accelerator driven sub-critical reactor systems. An effective magnetic shield is very important to achieve higher quality factor (Qo) of the cryomodule of a particle accelerator. The allowed value of field inside the cavity due to all external fields (particularly the Earth’s magnetic field) is ~15 mG or less. The goal of this PhD dissertation is to comprehensively study the magnetic properties of commonly used magnetic shielding materials at both cryogenic and room temperatures. This knowledge can …

Efficiency Evaluation Of A Magnetically Driven Multiple Disk Centrifugal Blood Pump, Kayla H. Moody

Theses and Dissertations

Heart failure is expected to ail over 8 million people in America by 2030 leaving many in need of cardiac replacement. To accommodate this large volume of people, ventricular assist devices (VADs) are necessary to provide mechanical circulatory support. Current VADs exhibit issues such as thrombosis and hemolysis caused by large local pressure drops and turbulent flow within the pump. Multiple disk centrifugal pumps (MDCPs) use shearing and centrifugal forces to produce laminar flow patterns and eliminate large pressure drops within the pump which greatly reduce risks that are in current VADs. The MDCP has a shaft drive system (SDS) …

Fabricating Superhydrophobic And Superoleophobic Surfaces With Multiscale Roughness Using Airbrush And Electrospray, Karam N. Almilaji

Theses and Dissertations

Examples of superhydrophobic surfaces found in nature such as self-cleaning property of lotus leaf and walking on water ability of water strider have led to an extensive investigation in this area over the past few decades. When a water droplet rests on a textured surface, it may either form a liquid-solid-vapor composite interface by which the liquid droplet partially sits on air pockets or it may wet the surface in which the water replaces the trapped air depending on the surface roughness and the surface chemistry. Super water repellent surfaces have numerous applications in our daily life such as drag …

Power Maximization For Pyroelectric, Piezoelectric, And Hybrid Energy Harvesting, Murtadha A. Shaheen

Theses and Dissertations

The goal of this dissertation consists of improving the efficiency of energy harvesting using pyroelectric and piezoelectric materials in a system by the proper characterization of electrical parameters, widening frequency, and coupling of both effects with the appropriate parameters.

A new simple stand-alone method of characterizing the impedance of a pyroelectric cell has been demonstrated. This method utilizes a Pyroelectric single pole low pass filter technique, PSLPF. Utilizing the properties of a PSLPF, where a known input voltage is applied and capacitance C_p and resistance R_p can be calculated at a frequency of 1 mHz to 1 Hz. …

Modeling Social, Economic, Technical & Environmental Components In An Energy System, Ange-Lionel Toba, Mamadou Seck

Engineering Management & Systems Engineering Faculty Publications

Energy system models have become the main supporting tool for energy policy. Modern challenges in energy policy require energy systems models that integrate technical, environmental and societal aspects of the energy systems. In this paper, we introduce a conceptual model for an energy system model that specifies the relationships between social, technical, environmental, and economic aspects of an energy system. This conceptual model presented in the IDEF0 language will serve as a basis for a computational energy systems model. © 2016 The Authors.

Optimal Configuration Of Inspection And Rework Stations In A Multistage Flexible Flowline, Md. Shahriar Jahan Hossain

LSU Master's Theses

Inspection and rework are two important issues of quality control. In this research, an N-stage flowline is considered to make decisions on these two issues. When defective items are detected at the inspection station the items are either scrapped or reworked. A reworkable item may be repaired at the regular defect-creating workstation or at a dedicated off-line rework station. Two problems (end-of-line and multistage inspections) are considered here to deal with this situation. The end-of-line inspection (ELI) problem considers an inspection station located at the end of the line while the multistage inspection (MSI) problem deals with multiple in-line inspection …

Energy Resources Use Metrics, Rahul Y. Nehete

Theses and Dissertations--Mechanical Engineering

Energy resources use has been considered as a key component of sustainable development. Data related to global, regional, state, sector, industry and process demonstrate that a significant reduction of energy resources for a given production rate in manufacturing processes requires an introduction of transformational technologies at the process level, propagating the impact to higher scales, leading not just to a gradual improvement of traditional technologies but to more sustainable development.

The study offers two approaches to the formulation of the limits of energy use in the context of sustainable development. The first is to construct a map of key selected …