Applied Mechanics Commons^™

Improving The Viability Of Continuous Fiber Reinforced Composite Materials In Extreme Temperature Applications And Additive Manufacturing, Ryan A. Warren

Shelby Hall Graduate Research Forum Presentations

Presentation slides for a presentation given at the 1st annual Shelby Hall Graduate Research Forum at the University of South Alabama.

Development Of Planetary Drive System For Formula Sae Electric Race Car, Brian Wong, Bradley Maruoka, Joshua Charles Fine, Madison Kai

Mechanical Engineering

Hub motors are compact electric motors mounted directly on each outboard wheel hub. Utilized in Formula SAE and Formula Student vehicles, this configuration offers several advantages over traditional drivetrains, including packaging optimization within the chassis, vehicle traction, and improved efficiency. Although hub motors are not yet common in 4WD vehicles, they are being explored for use in EVs and may become more common in the future. Every year, Cal Poly Racing FSAE designs and builds a formula-style race car. To improve drivetrain performance, the team is investigating the achievability of a hub motor 4WD drivetrain, requiring extensive research, development, and …

Numerical Simulation Of Airflow Properties Of The Naca 6420 Airfoil Using The Transition Rans K-Ε Model, Oluwaseyi O. Alabi, Saidat A. Salisu, Oyeyemi T. Aforolagba -Balogun, Temitope A. Ladigbolu, Ayotunde O. Fasina, Anas Bala

Al-Bahir

This study investigates the airflow properties around the airfoil using numerical simulation, addressing the longstanding challenge of accurately predicting transition phenomena in turbulent flows. The importance of this research lies in its potential to improve the design and performance of airfoils in various engineering applications, such as wind turbines, and aircraft. A custom 2-dimensional airfoil model was created using Airfoil instruments, featuring a 6% maximum curvature, 40% curvature position, and 20% thickness. COMSOL Multiphysics software performed computations at a velocity of over 19 hours, with data analyzed at 60-minute intervals. The Transition turbulent model was employed to simulate the airflow …

Effects Of Thermal Shock Protection Methods On Pressure Measurements In A Rapid Compression Machine, Myeji Materego

Tanzania Journal of Engineering and Technology (TJET)

The study investigates the impact of thermal shock protection methods on pressure measurements in Rapid Compression Machines (RCMs). It focuses on the performance of various pressure transducers, specifically 601A, 701A, 6061B, and 7005, under atmospheric initial conditions. The research emphasizes the importance of mounting techniques and coatings, revealing their significant effects on pressure trace accuracy. Special mounting adaptors for the pressure transducers were designed and manufactured, this enabled simultaneous measurements for all transducers to be made in a single compression stroke. Instantaneous pressure within combustion chamber was measured when air was compressed in RCM from initial pressure and temperatures of …

Development Of A Drive-Rod Unified Variable Pitch Control Mechanism For Small-Scale Horizontal Wind Turbines, Ayman I. Bakry, Mohamed Elfouly, Omar Mehrez

Journal of Engineering Research

Typically, small-scale wind turbines use either a breaking equipment or stall control methods once the wind speed exceeds its rated value. This is to limit the power extracted from the wind turbines which largely depends on the blades' shape and pitch angle. Most of small-scale wind turbines are of fixed pitch angle to avoid complexity and cost. In this work, a novel drive-rod unified variable pitch drive mechanism is proposed for blades pitch control for small-scale horizontal wind turbines. The mechanism is powered by a DC motor coupled with a lead screw which in turn is connected to the pitch …

Pd Controller Design For Automotive Magnetorheological Semi-Active Suspension System, Ayman I. Bakry, Emad M. S. El-Said, Ahmed Shehata Gad, Ahmed Abd Almoez, Omar Mehrez

Journal of Engineering Research

Recently, there is a tendency towards the utilization of magnetorheological (MR) dampers in electrical vehicles (EV) due to its adaptability of active control devices with lower requirement of large power sources compared to the active damping systems. This paper investigates the performance of the most used control technique for MR dampers used in EV, the PID controller, under different road conditions. In this investigation, the Dynamic-Damper-Motor System (ADM-EV) is used as the EV suspension system model. Meanwhile, modified Bouc-Wen model is used as the MR damper model. The design procedure for the optimum design of the system controller parameters is …

A Structural Evaluation And Design Optimization Of A Tow Bar For Disabled Snowmobiles, David M. Pevic

Masters Theses

Snowmobile tow bars are devices used to rigidly connect two snowmobiles, such that a disabled snowmobile can be recovered from a remote location with a working snowmobile. These devices, however, are not widely used or readily available. An existing tow bar design was evaluated and redesigned to improve its structural capacity and performance. This evaluation provided a baseline to quantify improvement and included Finite Element Analysis (FEA), Design Failure Mode and Effect Analysis (DFMEA), and Design for Assembly analysis (DFA). A review of existing snowmobile tow bar patents was also performed. An updated design was then fabricated and similarly evaluated. …

Feasibility Study Of A Smart Insole With Triboelectric Energy Harvesters For Early Flatfoot Detection, Mohammad Alghamaz

Mechanical Engineering Theses

This study introduces a self-powered smart insole system designed for real-time monitoring of foot health, with a specific focus on detecting flatfoot conditions. The insole integrates multiple triboelectric energy harvesters strategically positioned to capture electrical signals generated from ground reaction forces during daily activities such as walking, jogging, and running. Proof-of-concept testing was conducted on a single participant under two conditions: a healthy foot and a simulated flatfoot created by reducing the medial arch height by approximately 70\. In the healthy foot trials, the system demonstrated consistent and reliable performance, with negligible electrical output from the medial arch sensor, as …

Stress Analysis Of Anisotropic Inclusion Problems Using Complex Variables, Liming Chen

Mechanical and Aerospace Engineering Dissertations - Archive

This research presents an analytical framework for determining stress fields in an elastic medium containing a circular anisotropic inclusion embedded in an infinitely extended isotropic matrix subjected to far-field uniform stresses. Stress distributions within both the inclusion and the matrix are described using classical stress functions, widely employed in two-dimensional elasticity theory.

To manage the complexity of the mathematical derivations, symbolic computation software (Mathematica) is used to streamline the analysis and obtain closed-form solutions. This approach overcomes traditional computational barriers that have limited the practical application of complex variable methods (CVM) in elasticity.

The methodology builds upon the foundational work …

Nonlinear Bump Stiffness Model And Its Effect On Structural Stiffness And Nonlinear Rotordynamic Characteristic Of Foil Bearing, Woongeon Lee

Mechanical and Aerospace Engineering Dissertations - Archive

Bump foils are the most widely used in foil bearings, but the behaviors of bump foils are complicated, and their characteristics have been a focus of research for decades. Bump foils are usually modeled as stiffness and damping are accounted for through interactions with shaft eccentricity, loading, shaft speed and excitation frequency. These nonlinear characteristics of the bump foil of radial foil bearings can be observed during both manufacturing and operational processes because of their inherent structural properties such as bump geometry, forming process, age-hardening process and complicated contact behavior with bearing housing. These nonlinear characteristics are one of the …

Multi-Objective Design Optimization Of Hypoid Geared Rotor Systems, Xinqi Wei

Mechanical and Aerospace Engineering Dissertations - Archive

Hypoid gears represent one of the most generalized and complex forms of gearing, widely used for power transmission of skew shafts in vehicles, aviation, and marine transmission applications. Optimizing their performance remains challenging due to the complex tooth surface and contact behavior. Specifically, the design parameters of the tooth surface are multi-scale, interdependent, and subject to strong constraints, leading to strong nonlinearity and an ill-conditioned Jacobian matrix in the parameter identification model. Moreover, feasible and insensitive contact conditions are difficult to constrain due to the inherent complexity of local conjugate contact between the meshing surfaces. These challenges significantly increase optimization …

Ioto: Never Open A Stiff Lid Again, Gabriel Portugal

Libraries Award for Undergraduate Scholarship

Background: From baby food to pickles, food jars are a common find in American homes. Unfortunately,  the task of opening a stiff jar lid can be very difficult for consumers with lower grip strength, parkinsons,  or arthritis. While there are a variety of products on the market to help make this easier, there exist few jar  openers that can be used by these consumers. Objective: This project aimed to research and develop  (R&D) an improved hands-free jar opener that is accessible for consumers with the most advanced  cases of limited arm strength. Methods: R&D followed a Design Thinking approach with …

Analysis Of Ptfe Radial Lip Seals For Wheel Bearing Applications, Madison Vogt

Theses and Dissertations--Mechanical and Aerospace Engineering

A numerical analysis was conducted to investigate the viscoelastic effects of nonlinear materials on the sealing zone and contact pressure distribution of radial lip seals in a conventional geometric topology. The use of nonlinear materials in radial lip seal applications is desirable to improve operation and reliability of rotating machinery due to their high operating temperatures, chemical compatibility, and low friction coefficients. Examples include, but are not limited to, seals within industrial air compressors, turbine engines, aircraft landing systems, chemical processing equipment, and Freon pumps. This work focuses on analyzing the nonlinear viscoelastic response of pure Polytetrafluoroethylene (PTFE) and PTFE …

Growth Kinetics And Stability Of Metal Halide Perovskite Nanocrystals: Influence Of Stirring Speed And Water Exposure, You-Lin Huang

Theses and Dissertations--Mechanical and Aerospace Engineering

Cesium lead bromide (CsPbBr₃) perovskite nanocrystals (NCs) have garnered significant interest due to their exceptional optoelectronic properties, including high photoluminescence quantum yield, tunable bandgap, and excellent carrier dynamics. These attributes make them promising candidates for applications in light-emitting diodes, photovoltaics, and sensing technologies. However, optimizing their synthesis and improving their environmental stability remain critical challenges. This dissertation explores the growth kinetics of CsPbBr₃ NCs, focusing on the effects of stirring speed and water exposure on their structural and optical properties.

The synthesis of CsPbBr₃ NCs was performed using both mechanochemical (MC) and antisolvent methods, enabling an …

Machining-Induced Residual Stress Modeling Using Physics-Informed Neural Networks, Md Mehedi Hasan

Theses and Dissertations--Mechanical and Aerospace Engineering

Process-induced residual stress (RS) plays a critical role in determining the structural integrity, fatigue life, corrosion resistance, and dimensional stability of manufactured components. Tensile residual stress can be harmful to the machined workpiece by lowering fatigue strength, while compressive residual stress helps to prevent such issues. Therefore, accurate prediction and control of machining-induced residual stresses are essential for optimizing manufacturing processes and enhancing component performance. However, existing modeling approaches—empirical, analytical, and numerical—often have limited predictive accuracy, demand extensive calibration, or involve high computational costs. Traditional finite element analysis (FEA) provides modeling insights but is constrained by its high computational cost …

Damping Modulation Of Dampened Kapton Surfaces, Sebastian Esteban

Honors Undergraduate Theses

When droplets are vibrated or disturbed, they can exhibit a complex sloshing motion, an understudied behavior in drop physics. Droplet sloshing involves a complex combination of transverse and longitudinal motion that changes the droplet's effective weight on the surface the droplet is on. Our current understanding stems from preliminary work focusing on a cantilever beam of fixed thickness and variable viscosity of the liquid being sloshed. This investigation will focus on how variable cantilever thickness and constant viscosity for a liquid being sloshed affects the beam's deflection under consistent vibration. It will also investigate how the natural frequency of a …

Degradation Of Polymers And Polymer Composites In Extreme Environments, Ben T. Jewell

Dissertations, Master's Theses and Master's Reports

Polymeric materials are widely used in engineering applications due to their high strength-to-weight ratio, easy manufacturability, and cost-effectiveness. When incorporated into composites, they provide further performance enhancements, enabling use in demanding structural applications. However, long-term exposure to harsh environments including elevated temperatures, UV radiation, harsh chemicals, and radiation, can drive degradation processes that alter the material’s network structure, and in turn, degrade its mechanical performance. Exposure to thermo-oxidative conditions is one of the most common environments driving polymer degradation, leading to chain scission and crosslinking events, with the resulting oxidative products causing discoloration, reduced ductility, and changes in glass transition …

Dual Rotating Mount For Forward Facing Sonar, Javid Miller

Williams Honors College, Honors Research Projects

This project aims to create a mount for forward facing sonar (FFS) that will allow anglers to be able to rotate their sonar transducer manually, or in unison with their trolling motor. When in use with the trolling motor, the rotation will be transferred using a belt and pulley assembly. This assembly will be able to be disengaged to allow for manual rotation. This device is designed for use with the Minn Kota Ultrex trolling motor.

Experimental And Analytical Investigation Of Particle Dynamics In Newtonian And Non-Newtonian Fluids In A Taylor-Couette Cell, Andres F. Velez Mendoza

Dissertations and Theses

This doctoral dissertation investigates heavy particle sedimentation in Newtonian and non-Newtonian fluids, aiming to understand their behavior in Drilling Fluid (DF) systems used in oil and gas industry, where such phenomenon can lead to operational issues such as lost circulation, well control problems, and even blowouts. To simulate DF dynamics under operational conditions, this study utilizes a Taylor-Couette (TC) cell, which consists of a rotating inner cylinder and a stationary outer cylinder separated by a 9.0 mm annular gap. The TC cell allows for the investigation of the sedimentation behavior of spherical particles within both Newtonian fluids (deionized water and …

Horizontal Infiltration Of Water Through Porous Snow As A Gravity Current, Anthony Cheng

Dartmouth College Master’s Theses

On the surface of the Greenland ice sheet or around the margins of the Antarctic ice shelf, water infiltrates porous ice. It is important to understand this infiltration process since water populating the pore space of ice directly impacts the density, porosity, and wetness of ice. These properties influence the mechanics and tensile strength of ice, as greater amounts of infiltration result in faster or more widespread deformation events, which may lead to adverse climatic effects such as sea level rise and ocean current disruption. While studies have considered the thermodynamics and fluid mechanics of water vertically percolating through snow …