Mechanical Engineering Commons^™

Structural Sizing Of Post-Buckled Thermally Stressed Stiffened Panels, Walid Arsalane

Theses and Dissertations

Design of thermoelastic structures can be highly counterintuitive due to design-dependent loading and impact of geometric nonlinearity on the structural response. Thermal loading generates in-plane stresses in a restrained panel, but the presence of geometric nonlinearity creates an extension-bending coupling that results in considerable transverse displacement and variation in stiffness characteristics, and these affects are enhanced in post-bucking regimes. Herein a methodology for structural sizing of thermally stressed post-buckled stiffened panels is proposed and applied for optimization of the blade and hat stiffeners using a gradient-based optimizer. The stiffened panels are subjected to uniform thermal loading and optimized for minimum …

Assessment Of Mechanical Engineering Skills: A Synthesis Of Industry And Academic Graduate Level Curriculum Requirements, Francie Baker

Theses and Dissertations

Students who graduate with an advanced degree in mechanical engineering are a diverse group in their path to post-baccalaureate degree attainment. Some students choose to obtain their master’s or Ph.D. post bachelors, but before they enter the workplace. Others enter the workforce and return as full-time students or progress on their advanced degrees while maintaining part- or full-time employment. Current accreditation standards for undergraduate degree programs are part of a changing landscape of standards and professional requirements that have adapted and continue to adapt as programs prepare students to work in professional engineering fields. Advanced degrees do not have the …

Design, Construction, And Characterization Of A Test Stand Used To Test Filter Media, Adam W. Parsons

Theses and Dissertations

Air filters are routinely used to remove various aerosols ranging from radioactive particles to airborne viruses. The overall performance of a filter may be simplified to consider only two main performance characteristics: 1) the efficiency at which particles are removed by the filter, and 2) the filter’s resistance to air flow. Per the DOE Nuclear Air Cleaning Handbook, HEPA filters require a minimum filter efficiency of 99.97% for particles 0.3 micrometers in diameter. Understanding how filters will perform with respect to time and mass loading is essential towards building more robust filters that operate more efficiently and safely. Analyzing the …

Challenges And Signal Processing Of High Strain Rate Mechanical Testing, Barae Lamdini

Theses and Dissertations

Dynamic testing provides valuable insight into the behavior of materials undergoing fast deformation. During Split-Hopkinson Pressure Bar testing, stress waves are measured using strain gauges as voltage variations that are usually very small. Therefore, an amplifier is required to amplify the data and analyze it. One of the few available amplifiers designed for this purpose is provided by Vishay Micro-Measurements which limits the user’s options when it comes to research or industry. Among the challenges of implementing the Hopkinson technology in the industry are the size and cost of the amplifier. In this work, we propose a novel design of …

Lattice Boltzmann-Based Sharp-Interface Schemes For Conjugate Heat And Mass Transfer And Diffuse-Interface Schemes For Dendritic Growth Modeling, Nanqiao Wang

Theses and Dissertations

Analyses of heat and mass transfer between different materials and phases are essential in numerous fundamental scientific problems and practical engineering applications, such as thermal and chemical transport in porous media, design of heat exchangers, dendritic growth during solidification, and thermal/mechanical analysis of additive manufacturing processes. In the numerical simulation, interface treatment can be further divided into sharp interface schemes and diffuse interface schemes according to the morphological features of the interface. This work focuses on the following subjects through computational studies: (1) critical evaluation of the various sharp interface schemes in the literature for conjugate heat and mass transfer …

Experimental And Numerical Study Of Novel Coanda-Based Unmanned Aerial Vehicle, Zaid Feroz Siddiqi

Theses and Dissertations

To alleviate the thrust losses in radial direction experienced in conventional saucer-shaped Coanda Unmanned Aerial Vehicles (UAV), a rectangular, linear arrangement of the Coanda surface is adopted in the novel design. This arrangement minimizes the area change in the radial direction to recover such thrust losses. A prototype of the proposed UAV structure is 3D printed and assembled with a single 9-inch propeller. In addition, a custom-built dynamometer is designed specifically to measure propeller thrust under different loading conditions. Performance characteristics of the UAV are evaluated through static testing on the dynamometer which uses a load cell to measure the …

Student Understanding Of Kinematics: A Qualitative Assessment, Andrew Cashman, Tom O'Mahony

Publications

In engineering, kinematics is widely regarded as a fundamental topic with the literature agreeing that students possess a wide range in understanding of the topic. This study aims to take a second-order approach by understanding and exploring the qualitatively different ways in which students approach solving kinematics problems. Phenomenography was used to collect data through ten semi-structured interviews with early-stage mechanical engineering students. Following data analysis, four distinct categories of students’ approaches were identified; unstructured, framing the problem, strategic, and conceptual. It was found that these categories could be arranged in a hierarchy and were also supported by secondary epistemic …

Performance Projection Of A High-Temperature Co2 Transport Membrane Reactor For Combined Co2 Capture And Methane-To-Ethylene Conversion, Xin Li, Kevin Huang, Noah Van Dam, Xinfang Jin

Faculty Publications

Direct conversion of methane into ethylene through the oxidative coupling of methane (OCM) is a technically important reaction. However, conventional co-fed fixed-bed OCM reactors still face serious challenges in conversion and selectivity. In this paper, we apply a finite element model to simulate OCM reaction in a plug-flow CO₂ /O₂ transport membrane (CTM) reactor with a directly captured CO₂ and O₂ mixture as a soft oxidizer. The CTM is made of three phases: molten carbonate, 20% Sm-doped CeO₂ , and LiNiO₂ . The membrane parameters are first validated by CO₂ /O₂ flux …

Manual Material Handling Lift-Assist System For Occupational Exoskeleton, Erik Goes, Daniel Guthrie, Trevor Ward

Honors Capstones

It is no secret that lifting heavy objects is one of the premier causes of workplace injury, and the modern worker needs help to remain healthy. Workers need something they always have with them that makes their work safer as well as easier; our solution is an active lift-assist exoskeleton. The proposed exoskeleton design includes a military backpack exoskeleton frame, on which two actuators pull cables attached to end effectors that the operator will be holding. This system can adjust to conform to a wide variety of operator sizes, without restricting any of their range of motion. This leads to …

Nuclear Energy As A Reliable And Safe Source Of Power Generation, Sarup Dhungana

Honors Theses

There is a high demand of energy for generating civil applicable power in the world and in the USA, correspondingly. The world has been consuming various sources to extract the power to meet its demands. Most of the power sources include renewable and non-renewable sources like fossil fuels, natural gas, coal, water, solar, wind, and nuclear power. Although most of these sources have many advantages in terms of their capacity and cost of production, nuclear power can be categorized as the emerging driving force in the United States and in the world for power generation, because of its reliability and …

Novel Mobility Device For Conjoined Twins, Allyson Bowgren

Honors Capstones

This project provides a solution to a problem proposed by a pair of conjoined clients. With their desire to become fully independent, the clients need an improved mobility device. Being joined at the head, moving around was always difficult for them and their situation did not get any better after an accident left one of them immobile. Their current device was a decent and quick solution at the time it was first needed. However, since its conception the device quickly became obsolete, and they are now in need of a more effective device that allows them to travel easier. This …

Center For Manufacturing Excellence Capstone Project: Sec Rivals Checkers, Ward Winstead

Honors Theses

Each year, the seniors in the Haley Barbour Center for Manufacturing Excellence complete a capstone project. A team comprised of seniors in varying disciplines work to develop a business model focused on producing a specific product. This team, SEC Rivals Checkers, chose to produce wooden checker boards where each half of a board is custom to a specific SEC school. These halves were designed to be interchangeable, so a variety of different combination could be created when utilizing the product. Through initial marketing analysis, cost estimation, prototyping, and process development, the original SEC Rivals Checkers idea was developed into a …

Interaction Beyond Nearest Neighbor In Periodic Structures, Sudesh Pathak

Honors Theses

Periodic structures have been of particular interest to researchers and engineers due to their interesting vibrational characteristics leading to applications, namely acoustic filters, and waveguides. Many studies on the interaction of nearest neighbors have been performed. However, such studies are insufficient to understand the variation of band gaps and the maximum number of wave vectors for each frequency. The complex band structure obtained from the interaction beyond nearest neighbors can assist in the development of sophisticated acoustic technologies. This paper primarily emphasizes the study of such interactions with the development of mathematical models based on electrostatic forces, supported by the …

Customized Sidearm Case: Leading A Cme Capstone Team From Concept To Production, Robert B. Sharp

Honors Theses

The goal behind this thesis is to document and analyze my performance as the project manager for the Customized Sidearm Case capstone team during the Center for Manufacturing Excellence’s senior capstone experience. The capstone experience begins the fall of students senior year where a select number of product ideas submitted by the students are chosen, and teams are built around these projects. The objective of the project is to walk a product from the concept phase through the entire design process resulting in a full-scale production run during the spring semester. My product pitch of a wooden sidearm case, customized …

Developing New Crutch Tip Design For Overall Increased Stability And Improved Movement On Different Terrains, Lauren Skinner

Honors Theses

Crutches are a mobility assistive device that are often used in various situations, such as post- surgical rehabilitation and recovery after injury. The current crutch tip design that is used on today’s crutches are often unstable and do not provide quality movement on different terrains, such as snow, ice, mud, and wet surfaces. These problems would be solved with a new tip design that could be attached to existing crutches or manufactured with the crutch itself. The team’s solution to this problem is a crutch tip with modular parts. The tip would attach to the shaft of the crutch like …

Fea Analysis On A Beam Of Hexacopter Drone Frame, Aicha Chahbi El Alaoui, Taymae Ben Messaoud

ME 4233/6233 Fundamentals of FEA

Our project covers the research made, a deep analysis, the structural design, modeling, and design of a hexa copter, which has six degrees of freedom. In order to improve the drone’s dynamics and efficiency, an analysis will be conducted on one beam constituting the drone using Abacus.

Characteristics Of The Wake Of An Inclined Prolate Spheroid In Uniform Shear Flow, Zhe Wang, Jianzhi Yang, Helge I. Andersson, Xiaowei Wu, Yuxin Wu, Liping Wang, Minghou Liu

Mechanical and Materials Engineering Faculty Publications and Presentations

Flow around an inclined 5:2 prolate spheroid with the incidence angle α = 45° is numerically investigated in a uniform shear flow. The Reynolds number based on the inflow center velocity Uc and the volume-equivalent sphere diameter De of the spheroid are considered at Re = 480, 600, 700, and 750. The non-dimensional shear rate K is ranged from 0 to 0.1. Five qualitatively different wake modes are observed, including a new mode characterized by multi-periodic shedding of hairpin vortices with regular rotation of the separation region. In general, the wake transition is suppressed with increasing shear rate. …

Automated Robotic Light Bulb Testing Platform, Agha I. Akram, Muhammad Ali Ummy

Publications and Research

The main purpose of this project is to create a functional prototype of a multilayered system that incorporates aspects of electrical, mechanical, and computer engineering technology. The main objective of the system is to be able to determine whether a light bulb is working or not. The building blocks of this system are a robotic arm that is able to slide along a rail (for added mobility), a conveyor belt, and an electromechanical device that holds and tests light bulbs. Initially, the robot arm picks up a light bulb and places it into the holder which then tests it. A …

Exploring Solidworks Simulation And Structural Analysis Tools To Predict Real-World Physical Behaviors, Itay Rubin

Publications and Research

Computer Aided Design (CAD) Software can optimize the product design process prior to manufacturing. This project examines engineering solutions using CAD software called SolidWorks. It simulates how the product will behave under a variety of engineering constraints. These simulations allow designers to optimize performance, cost, and speed efficiencies. The project uses simulations and finite element analysis to replicate real world behavior. It presents high-level capabilities in the design process, exposing new engineers to simulation tools that are available and relevant in mechanical engineering design. This project required independent research to obtain an advanced understanding of the software interface and capabilities.

Electromechanical Fatigue Properties Of Dielectric Elastomer Stretch Sensors Under Orthopaedic Loading Conditions, Andrea Karen Persons

Theses and Dissertations

Fatigue testing of stretch sensors often focuses on high amplitude, low-cycle fatigue (LCF) behavior; however, when used for orthopaedic, athletic, or ergonomic assessments, stretch sensors are subjected to low amplitude, high-cycle fatigue (HCF) conditions. As an added layer of complexity, the fatigue testing of stretch sensors is not only focused on the life of the material comprising the sensor, but also on the reliability of the signal produced during the extension and relaxation of the sensor. Research into the development of a smart sock that can be used to measure the range of motion (ROM) of the ankle joint during …

A Review Of Ductless Mini Split Hvac System, Manoj Bhandari, Nelson Fumo

Mechanical Engineering Faculty Publications and Presentations

Although a conventional ducted system is the HVAC system used by most of the household in the United States, the ductless mini split system is gaining popularity in the market. The ductless mini split heat pump system consists of an outdoor unit that provides hot or cold refrigerant into a house to one or more wall- or ceiling-mounted indoor fan units. Ductless mini splits can have several advantages over conventional systems including improved thermal comfort, performance, and energy saving. There have been several studies and research in the field of ductless mini splits to learn about the advantages and disadvantages …

Probing Myosin Ensemble Mechanics In Actin Filament Bundles Using Optical Tweezers, Omayma Al Azzam, Janie C. Watts, Justin E. Reynolds, Juliana E. Davis, Dana N. Reinemann

Faculty and Student Publications

Myosins are motor proteins that hydrolyze ATP to step along actin filament (AF) tracks and are essential in cellular processes such as motility and muscle contraction. To understand their force-generating mechanisms, myosin II has been investigated both at the single-molecule (SM) level and as teams of motors in vitro using biophysical methods such as optical trapping. These studies showed that myosin force-generating behavior can differ greatly when moving from the single-molecule level in a three-bead arrangement to groups of motors working together on a rigid bead or coverslip surface in a gliding arrangement. However, these assay constructions do not permit …

Comparative Analysis And Dynamic Response Of Abs Under Uv Light Degradation Using Shock Tube, Greer Lauber

Honors Theses

The purpose of this study was to examine the dynamic response of acrylonitrile-butadlene-styrene (ABS) when exposed to UV light. Impact-Resistant Easy-to-Form ABS sheets were tested using a Shock Tube. Three samples were tested at no UV light exposure and three were tested after 15 days of being exposed to rapid UV degradation rays. All samples were tested at a shock wave equivalent to 400 psi. The results showed that the UV damaged samples experienced a decrease in strength and energy absorption in comparison to the non-UV damaged samples. The average peak load for the non-UV degraded was 1261.89 Newtons and …

Efficient Energy Harvesting With Applications In Vibration And Implantable Biosensors, Mohammad Atmeh

Mechanical Engineering Theses

The world has stepped into the fourth industrial revolution in many ways such as using the internet of things (IoT) in various applications, and removing the rechargeable power sources seeking for batteryless systems. Since energy is widely abundant around us and it is going to waste, numerous of recent studies have been conducted to propose sustainable solutions to harvest the free ambient power from the surrounding and convert it into electricity. Heat energy, kinetic energy, and radio waves are examples of these potentially harvestable energy sources. Mechanical vibrations represent one of the most plentiful forms of kinetic energy that can …

Leverage Topology Optimization To Maximize Structure Design Efficiency, Teng Li, Saad Aqerrout

ME 4233/6233 Fundamentals of FEA

This paper presents the topology optimization method to improve the efficiency of mechanical structure design.

Computational Mechanics Implementation Of Performance Based Testing In Massive Concrete Structures, Gabriel Y. Riveros

ME 4233/6233 Fundamentals of FEA

Most of the nation’s critical water resource infrastructures are near or have exceeded their design lives. Consequently, there is a huge need for the development of assessment procedures that will change the way dams are maintained and operated with the intent of extending the service life. This is crucial for ensuring the safety and security of our nation’s public services. The combination of advanced computational mechanics and performance based testing (PBT) methods can be used to investigate the existing conditions of large concrete structures.

Performance based testing (PBT) is a new and innovative non-destructive testing technique that we are implementing …

Comparison Of Johnson-Cook And Linear Elastic-Perfectly Plastic Material Models For Ballistic Impact Case, Logan J. Callahan, Marella Failla, Harrison Williams

ME 4233/6233 Fundamentals of FEA

In an effort to characterize the linear elastic-perfect plastic (J2) and Johnson-Cook (JC) Strengthening and Damage material models for an Aluminum target material being struck by a steel penetrator, finite element analysis (FEA) will be used to simulate the residual velocities from ballistic impacts, using various velocities of the penetrator. The object is to define the point at which the J2 material model is no longer accurate and therefore requires the use of the JC material models.

Numerical Analysis Of Taylor Impact With Various Nose Shapes, Jean C. Santiago Padilla, Erik M. Chappell

ME 4233/6233 Fundamentals of FEA

The Taylor impact test is an experimental technique used to determine dynamic material response and to validate constitutive models used in numerical simulations. It generally consists of shooting a cylinder rod of a select material against a rigid target at different velocities. After impact, the plastic deformation of the cylinder is recorded and is directly compared to numerical predictions. Another application for Taylor impact was proposed by Li et al. (2021) where the nose shape of the cylinder is modified to create different loading environments that can test electronic equipment in penetration weapons. FEA models where designed in ABAQUS/Explicit to …

Analysis Of Preload In Bolted Joints Under Impulse, Albert Dusseault

Thinking Matters Symposium

From transportation to storage to construction, bolted joints are utilized everywhere. Bolted joints in closures such as pressure vessels/tanks require a preload, or a specific amount of tightening of the bolts to seal the vessel when pressurized to avoid leaking. Low preload can result in joint loosening whereas high preload can result in yielding. Therefore, finding feasible and even better optimal values of preload is of great practical importance. In an earlier work in 1996, this problem was tackled with an exponentially decaying pressure applied on a pressure vessel closure. In the present analysis, however, the pressure variation is considered …

Molecular Dynamics Study Of Melting Behavior Of Planar Stacked Ti–Al Core–Shell Nanoparticles, Huadian Zhang, Yu Chen Su, Yiwei Han, Shan Jiang

Faculty and Student Publications

Selective laser sintering (SLS) is one of the most commonly used methods in additive manufacturing, due to its high prototyping speed and applicability to various materials. In the present work, molecular dynamics (MD) simulations were performed to study the thermodynamic behaviors of the planar stacked nanoparticles (NPs) model and explore the potential capability of the SLS process with nano-sized metal powders in the zero-gravity space environment. A multi-particle model of titanium–aluminum (Ti–Al) core–shell NP with a particle radius of 50 Å was constructed to investigate the characteristics of the melted pattern during sintering. Two patterns with different spatial densities were …