Mechanical Engineering Commons^™

Elevate Hardcase, Caleb J. Bailey, Colby M. Cordoba, Marissa Mccleod, Shaan Sandhu

Mechanical Engineering

The Elevate Hardcase project developed a portable mechanical elevation system that allows users to access rugged hard cases at a comfortable working height without needing a separate table or placing the case on uneven ground. The design focuses on improving ergonomics, portability, stability, and quick setup for users in field environments such as photography, hunting, and maintenance. Through customer research, concept development, prototyping, analysis, and testing, the final system was designed to support a loaded hard case, provide height adjustability, remain stable on uneven terrain, and be deployed by a single user in under five minutes. The final prototype demonstrates …

Design And Production Of A Carbon Fiber Longboard, John R. Beebe, Jacob Williams, Julia Stradinger, Vince Fitchtel, Jordan Cochran

Honors Theses

This thesis contains an overview of the design, prototyping, and manufacturing of a carbon fiber long board. The purpose of this capstone was to create a viable product for the real-world market and then determine how to manufacture it at scale with sustainable financial practices. In order to accomplish this task, engineering, accounting, and manufacturing challenges had to be overcome throughout all stages. The production process involved the carbon fiber layup, baking, water jet cutting, and assembly of the carbon fiber longboard. In order to optimize this process, continuous improvement and lean manufacturing problem solving techniques were applied. After a …

A Maximum Energy Release Rate Computational Framework For Fatigue Crack Trajectory And Life Prediction Under Mixed-Mode Proportional And Nonproportional Loading, Nahla Helmy Matar

Theses and Dissertations

The problem of mixed-mode fatigue crack growth has been a persistent research challenge. The determination of fatigue crack propagation direction directly impacts the safety and integrity of components and structures, making it crucial in various industrial applications, including welded drilling pipes, aerospace, and automotive engineering. Unlike uniaxial loading, mixed-mode cracks tend to change direction frequently (kinking), and nonproportional loading adds to the complexity of the problem. This research aims to estimate the crack propagation direction and fatigue crack life in linear elastic materials subjected to mixed-mode (I+II) loading conditions under proportional or non-proportional cyclic loading. Numerical software was developed based …

Power At Sea Develop Phase, Jake Lauer, Isabella Heinemann, Bailey Gargasz, Zachery Boyer

Mechanical Engineering

This project develops a renewable, wave-powered charging system designed to extend the mission duration of Autonomous Underwater Vehicles by eliminating the need for frequent manual battery replacement. Building upon a prior oscillating water column prototype from the CONCEPT phase, the team redesigned and tested an improved system capable of converting wave-induced air motion into electrical power using a Wells turbine. Key enhancements include doubling the column diameter to increase displaced air volume, integrating a flared inlet and bi-directional nozzle to improve airflow, and selecting corrosion-resistant materials suitable for long-term deployment in marine environments. Multiple prototypes were constructed and evaluated through …

Physics-Data-Hybrid Modeling And Control For Vtol Aircraft, Samantha Dawn Burton

All Graduate Theses and Dissertations, Fall 2023 to Present

Vertical takeoff and landing (VTOL) aircraft are hybrid aircraft having both a helicopter flight mode and a fixed-wing plane flight mode. The objective of this dissertation is to examine and evaluate a new approach, physics-data-hybrid (PDH), for VTOL aircraft modeling and control. The PDH approach combines traditional, physics-based methods (Newtonian mechanics) with data driven methods (a machine learning technique called a Koopman operator model) to create an efficient and accurate modeling and control framework—mitigating the disadvantages of the purely physics-based and purely data-driven methods. The PDH approach is used to model scenarios when the VTOL aircraft transitions between helicopter mode …

Polymer Nanocomposite Dielectrics For High-Temperature Superconducting Cables: Cryogenic Characterization And Testing Environment Development, Jared R. Ericksen

Theses and Dissertations

High-temperature superconducting (HTS) cables require dielectric insulation materials that can withstand cryogenic operating environments while maintaining electrical reliability, mechanical stability, and manufacturing compatibility. This thesis investigates polyamide-based polymer nanocomposites as candidate HTS cable insulation materials and develops cryogenic testing platforms for evaluating thin-film dielectrics at reduced temperatures. Two silicon-based filler systems are studied: sol-gel-derived silicon dioxide (SiO 2 ) nanoparticles and polyhedral oligomeric silsesquioxane (POSS). Dielectric breakdown behavior is evaluated under DC and AC high-potential testing, while mechanical behavior is assessed through tensile testing. The results show that PA/SiO 2 nanocomposites provide the strongest overall balance of mechanical reinforcement and …

Design And Fabrication Of 3d Bioprinted Scaffold: Experimental And Machine Learning Methods, Mohan K. Dey

LSU Doctoral Dissertations

The development of reliable hydrogel-based scaffolds for extrusion bioprinting remains limited by the poor structural fidelity of low-viscosity bioinks and the lack of robust, high-throughput quality evaluation methods. This dissertation can resolve such challenges by developing the combination of optimized hydrogel formulations, cryogenic-assisted bioprinting, and artificial intelligence (AI)-based scaffold evaluation to the use of tissue engineering and preclinical cancer modelling applications. To assess the rheological behavior, printability, mechanical properties, and biocompatibility of the alginate – gelatin (Alg–Gel) system, a novel system of hydrogel was developed and characterized using Alg–Gel hydrogel system. The 7% alginate, 8% gelatin mixture was found to …

An Investigation Of Pelvic Kinematics And Implications For Total Hip Arthroplasty, Kathryn Holland Colone

Electronic Theses and Dissertations

Total hip arthroplasty (THA) is one of the most commonly performed orthopaedic procedures, with approximately 500,000 surgeries performed annually in the United States alone. Although THA is widely regarded as highly successful, postoperative complications persist, highlighting the multifactorial nature of THA outcomes. Previous studies have demonstrated the importance of implant positioning and soft tissue mechanics, yet challenges remain in optimizing surgical decisions on a patient-specific basis. Recent advances in surgical planning tools have shifted the focus of preoperative planning toward optimizing patient-specific outcomes, highlighting the need to better understand how patient anatomy, surgical technique, and joint mechanics interact to influence …

Effects Of Ankle Actuation On Stability And Gait Dynamics In Oscillatory Bipedal Walking, Guillermo E. Selva Barrantes

Electronic Theses and Dissertations

Bipedal locomotion remains one of the most challenging problems in robotics and biomechanical modeling due to its inherent instability, underactuation, and the complexity of human gait dynamics. This study presents the design and control of a planar bipedal walking model developed to analyze the role of ankle control in achieving stable and human-like walking patterns. Two configurations were investigated: a five-link point-foot model and a seven-link model that incorporates anatomically inspired feet with heel and toe contact points. Both models were formulated using Lagrangian dynamics and integrated with a compliant contact and friction model to reproduce realistic ground interaction forces. …

The Influence Of Urban Form On The Distribution Of Air Pollutants, Takin Khosrownia

Dissertations and Theses

Urban form exerts strong control on how pollution from outside a city is transported through the urban canopy and experienced at street level. This study uses the prognostic microclimate model ENVI-met to simulate an active pollutant released from an upwind rural highway and advected through an urban region represented by ten Local Climate Zone (LCZ) types. The cases share identical inflow and are isothermal, dry, and non-vegetated, so that differences among them are attributable to building morphology alone. PM2.5 is the primary exposure diagnostic. Its transport and ejection are characterized through plan-view contours, vertical plume sections, and spatially averaged streamwise …

Measurement Of Pollution Emissions From Natural Gas Stoves: Preparation For An Induction Cooktop Intervention Study, Jessica Zanella Lorensi

Dissertations and Theses

Humans spend ∼90% of their time enclosed in buildings. Indoors environments can be a source of pollutant which can affect health and productivity. Appliances that combust fossil fuels indoors, like stoves, are a critical source of a range of pollutants, like carbon monoxide (CO) and nitrogen dioxide (NO₂). In the US, the usual cooking fuel is natural gas (NG), presented in more than 30% of households in the country. Some studies in the literature linked cooking pollutants, including those specific to gas combustion, to various health conditions, including heart and respiratory diseases. Nitrogen dioxide, for example, can be …

Experimental Material Analysis And Load Monitoring Of Polyurethane–Steel Belts Subjected To Static And Cyclic Dynamic Loading: Implications For Continuous Mooring Line Systems In Wave Energy Converters, Youssef Mohamed

Electronic Theses and Dissertations 2020 - Present

This study experimentally investigates the mechanical and viscoelastic behavior of a steel-cord-reinforced polyurethane synchronous belt capable of withstanding continuous cyclic loading as a potential compliant mooring element for WEC applications. Quasi-static and cyclic tensile tests were conducted to characterize the belt's mechanical response. The quasi-static determined that the belt behaved as a stiff, low-strain tensile member. Under approximately 100 kgf, the belt extended by about 0.107mm over a 250mm gauge length, apparent tensile modulus of 5.41GPa, an axial rigidity of 2.44MN, and an equivalent line stiffness of 9.75MN/m. Cyclic tensile testing showed high dynamic stiffness with stiffness-transfer ratio of 0.924. …

Development And Testing Of A Computer Vision Pose Estimation System For Planar Mobile Robots, Andrew Jones

Master's Theses

This thesis details the development and testing of a computer vision-based real-time pose estimation system for differential drive robots. A single camera with a fisheye lens is used to locate ArUco markers placed at fixed locations and attached to robots. Using the OpenCV library, the Perspective-n-Point (PnP) problem is solved to facilitate the transformation of 2-D robot positions in an image to world-frame coordinates. An analytical solution is presented to estimate robot poses based on a single PnP solution, rather than solving the PnP problem for each pose estimate. Pose information is relayed to individual robots using a multi-microcontroller architecture …

Thermal Conversion Of Cotton Gin Byproducts Into Liquid Fuels And High-Value Chemicals, Emmanuel Asare

Mechanical Engineering Theses

In this study, we performed fast pyrolysis, catalytic fast pyrolysis (CFP), and catalytic hydropyrolysis (CHP) of cotton gin byproducts (CGB) to investigate their conversion into hydrocarbon-rich liquid fuels and high-value aromatic chemicals. Five CGB fractions (CC1, CC2, SM, TM, and FCGB) were collected from different stages of cotton ginning operation and characterized by proximate, ultimate, and higher heating value (HHV) analysis. The feedstocks contained 41.5 44.8 wt.% carbon, 54.2–58.5 wt.% volatile matter, 6.0–15 wt.% ash, and higher heating values of 15.2–16.8 MJ kg⁻¹. All pyrolysis experiments were performed using a Pyroprobe 5200 coupled with GC-MS/FID, while catalyst loading, hydrogen pressure, …

A Cfd-Dem Framework For Characterizing Nanoparticle Adhesion Effects On Creeping-Flow Permeability In Composite Manufacturing, Gavin Stoker

All Graduate Theses and Dissertations, Fall 2023 to Present

Modern aircraft, spacecraft, and high-performance vehicles are increasingly built from composite materials, engineered combinations of plastics and fibers that are lighter and stronger than traditional metals. Researchers are now pushing these materials further by mixing in microscopic particles thousands of times smaller than a human hair, called nanoparticles, to make them even tougher and more resistant to damage. The challenge is getting those nanoparticles distributed evenly. During manufacturing, liquid plastic resin is pumped through a network of tightly packed fibers, carrying the nanoparticles along with it. But nanoparticles tend to clump together and stick to surfaces as they travel, clogging …

Residual Stress Informed Reconstruction And Failure Analysis Of Manufacturing Induced Composite Meso-Structure, Mohammad Nazmus Saquib

Mechanical & Aerospace Engineering Theses & Dissertations

A physics informed, AI-augmented framework is developed to enable digital twins of molded composite materials by linking manufacturing induced residual stresses to a local meso-structure. By reconstructing and explicitly modeling these architectures, the framework reveals how processing driven meso-structural variability governs stiffness, damage evolution, and failure. The work focuses on two technologically important systems: prepreg platelet molded composites (PPMC), characterized by inherently stochastic platelet architectures, and 2/2 twill glass fiber/PA6 organosheets, whose periodic but locally variable weave geometry influences mechanical response. For PPMC, the Residual Stress Informed Microstructure Reconstruction (ResIMiR) framework is introduced, combining thermoelastic strain fields with deep learning …

High-Throughput Characterization Of Creep In Additively Manufactured 316l Stainless Steel, Raushan Kumar Singh

All Graduate Theses and Dissertations, Fall 2023 to Present

Advanced materials are widely used in industries such as nuclear energy, aerospace, and automotive engineering, where components are exposed to extreme temperatures and stresses over long periods of time. As new materials continue to emerge, researchers need efficient ways to evaluate their mechanical performance so they can be used safely and effectively. Among several mechanical challenges, creep is a major concern in these conditions. Creep is a type of mechanical failure in which materials gradually deform when exposed to high temperatures and constant load. Conventional methods for evaluating creep typically involve testing a single specimen at a time, which can …

Theory, Implementation, And Practical Applications Of A Modern Parabolized Navier-Stokes Code, Logan B. Freeman

All Graduate Theses and Dissertations, Fall 2023 to Present

The Parabolized Navier-Stokes (PNS) method is a specialized computational approach for solving the equations that govern fluid flowing faster than the speed of sound, known as supersonic flow. By leveraging unique physical properties of supersonic environments—specifically that information cannot travel upstream—this method allows for significantly more efficient calculations than traditional approaches. Supersonic flows are important for many military and civilian applications including hypersonic weapons, high-speed passenger aircraft, and reentry. This thesis provides a comprehensive review of the two-dimensional PNS formulation, detailing the mathematical derivation and its practical implementation for solving flow problems. Through performance analysis and error assessment, this research …

Sensitivity Analysis Of A Low-Power Wireless Capacitive Charging System To Inform Thermal Limitations And Battery Size Reduction Potential For Electric Passenger Vehicles, Karmen Teuscher

All Graduate Theses and Dissertations, Fall 2023 to Present

The purpose of using electric vehicles instead of internal combustion engine vehicles that burn gas is to reduce pollutants in the air and potential environmental impacts such as climate change. EVs produce much less air pollutants than ICEVs but manufacturing the EV batteries and the repeated recharging still contributes to the overall air pollution.

Capacitive power transfer systems can wirelessly charge vehicles through the road as they drive along highways or stop at traffic lights. If vehicles charge as they drive, an opportunity opens to reduce the size of the battery while maintaining the same driving range. Reducing the size …

Toward Risk-Informed Design Of Supercooling Heat Exchangers: Statistical Inference And Experimental Investigation Of Heterogeneous Ice Nucleation, Daniel B. Gardner

All Graduate Theses and Dissertations, Fall 2023 to Present

Ice-based cooling storage systems can reduce electricity costs and grid strain by making ice during off-peak hours and using it for air conditioning during the day. One promising design works by chilling water below its freezing point as it flows through a heat exchanger, then allowing it to freeze in a separate storage tank. The challenge is that the chilled water can freeze prematurely inside the heat exchanger itself, blocking the flow and shutting the system down. Preventing this unwanted freezing requires understanding how and where ice begins to form on surfaces, a process called nucleation.

This dissertation investigates ice …

Time-Frequency Analysis Of Arterial Pulse Signals Of Cardiovascular Disease Patients Measured By A Microfluidic-Based Tactile Sensor, Md Mahfuzur Rahman

Mechanical & Aerospace Engineering Theses & Dissertations

This dissertation presents a single-degree-of-freedom (SDOF) based time–frequency analysis framework that can simultaneously extract a comprehensive set of cardiovascular autonomic indices from arterial pulse wave recordings obtained at rest and post-exercise, supporting non-invasive monitoring of autonomic recovery during cardiac rehabilitation. The framework rests on three technical contributions.

First, an SDOF analytical model of motion artefacts quantifies two physically distinct distortion mechanisms: additive baseline drift and Time-Varying System Parameter (TVSP) generated distortion of the Tissue-Contact-Sensor (TCS) stack. Baseline drift is slowly varying and removable by filtering; TVSP distortion rides on all harmonics of the true pulse signal and cannot be removed …

Prompt-Driven Tabletop Robotic Manipulation With A Structured Llm Interface And Visual Verification, Tomas Franco

Master's Theses

Creating a tabletop robotic manipulation system that connects language goals to robot actions is a challenging problem. Large language models can interpret mission objectives and reason through actions, but when placed directly in control of hardware they can produce hallucinated commands that result in unsafe behavior without the proper safeguards.

This thesis presents a constrained LLM-guided manipulation system built around the Quanser Qarm, a four degree of freedom manipulator with a mounted Realsense RGB-D camera and a gripper with readable current. Every decision made by the LLM planner is routed through a gated command interface that restricts the model to …

Extended Adaptive Oscillator Framework For Gait Phase Estimation With Adaptive Coupling And Transition Detection Across Locomotion Tasks, Nikhila Radha Krishnan

All Theses

Gait phase is a human-inspired physical variable that describes the instantaneous position of a person within a gait cycle. Adaptive oscillators have been widely used for gait phase estimation due to their ability to synchronize with periodic and pseudo-periodic biomechanical signals and generate monotonically increasing cyclic phase values. Typically, the performance of adaptive oscillators is strongly influenced by coupling strength, a parameter that bridges a trade-off between convergence speed and steady-state variability of the estimated stride frequency. In gait assistive applications, stride frequency estimation must be sufficiently fast to enable phase-based assistance while achieving a stable stride frequency estimate. The …

Smart Process Planning For Automated Fiber Placement, Matthew J. Godbold

All Dissertations

Automated Fiber Placement (AFP) is a preeminent manufacturing technology for producing high-performance composite structures, offering precise material placement, reduced waste, and the potential for highly optimized lightweight designs. While AFP has been widely adopted in aerospace applications, its broader use across industries such as automotive, wind energy, maritime, and sporting goods remains limited. A key barrier to wider adoption is the traditional separation of design, manufacturing, and inspection processes, which drives up cost and results in inefficiencies, sub-optimal designs, and limited feedback between lifecycle stages. In current practice, manufacturing is treated as an isolated process, disconnected from early-stage design decisions …

Integrated Power, Energy, And Thermal Management For Autonomous Hybrid Off-Road Vehicles: Multi-Timescale Modeling, Predictive Control, And Resilient Thermal Design, Anirudh Sundar

All Dissertations

Electrification and autonomy are increasingly important for off-road vehicles operating in construction, agriculture, mining, defense, and other demanding environments. These platforms must deliver high tractive power under unstructured terrain, harsh ambient conditions, low-speed operation, and large auxiliary loads. While hybrid and electrified powertrains offer improved efficiency, mobility, and auxiliary power capability, they also introduce significant challenges in managing tightly coupled power, energy, and thermal subsystems. In particular, lithium-ion batteries, power electronics, electric machines, and internal combustion engine-generator systems operate across different temperature limits and timescales, requiring coordinated management to ensure efficiency, durability, and safe operation. This dissertation develops modeling, planning, …

Microstructural Shielding And Advanced Fatigue Crack Analysis In The Presence Of Deformation Twinning, Seyed Ali Asli

All Dissertations

Design methods to mitigate fatigue failures have remained relatively stagnant, as engineers have relied on existing continuum-level models and adhered to the damage tolerance design methodology. Although damage-tolerant design has led to increased safety, extended component in-service life, and better life predictions, it still relies on maintenance routines to identify dangerous cracks. This research aims to test the hypothesis that bundles of deformation twin boundaries will increase the resistance to fatigue crack growth (FCG). Slip and twinning are two dominant mechanisms of plastic deformation in metals. Slip is more common in materials with face-centered cubic (FCC) crystal structures at room …

Investigating The Impacts Of Information Framing And Representation On Multi-Stakeholder Decision-Making For Tradespace Exploration, Meredith G. Sutton

All Dissertations

Tradespace exploration (TSE) is a decision-making process used in engineering design to search through a tradespace, containing all potential solutions to a design problem and their performance evaluations, in order to select optimal or near-optimal solutions. Solution optimality is driven by a desire to maximize the overall utility of a solution, which often cannot be done without making tradeoffs or compromises. The TSE process requires vast amounts of information which can be difficult to generate and understand, often leading to challenges including information overload, delays in decision-making, and suboptimal decisions, even for the most experienced designers. To address the challenges …

A Hybrid Machine Learning-Based Feasibility Prediction Of 3d Mechanical Designs Using Scalar And Geometric Features, Md Mohsin Uddin Fahim

Open Access Theses & Dissertations

The computational bottleneck of structural feasibility screening frequently hinders the transition from a digital 3D model to a physically manufactured component. Traditionally, engineers have relied on either overly rigid heuristic constraint checks or computationally exhaustive finite element simulations. To address this inefficiency, this thesis proposes and validates a hybrid machine-learning framework to predict the structural manufacturability of 3D mechanical designs. Moving beyond the conventional reliance on isolated scalar parameters, the proposed methodology extracts and integrates both scalar manufacturing constraints (e.g., tolerance, minimum feature thickness) and spatial geometric descriptors (e.g., bounding volume, aspect ratio) directly from STL mesh data. Utilizing a …

Investigating Simulated Natural Gas Combined Cycle Plants (Ngcc) Performance To Address The Intermittency Of Renewables, Patrick Washington

LSU New Orleans Theses and Dissertations

The inherent intermittency of wind and solar energy challenges grid stability, requiring flexible support from natural gas combined cycle (NGCC) power plants. The objective of this study is to develop a method for evaluating the turn-down performance of the NGCC system and to identify effective strategies to operate multi-island NGCC plants to respond to intermittent power demand fluctuations driven by renewable energy integration. The simulation tool was validated against benchmark U.S. Department of Energy (DOE) subcritical Rankine cycle and NGCC cases. The methodology was then applied to evaluate part load operation, inlet fogging, hydrogen blending, and multi-island dispatch for a …

A Verification And Validation Framework For Model-Based Systems Engineering Using Executable Architecture Models And Integrated Simulation, Michael O. Cruz

Open Access Theses & Dissertations

Model-Based Systems Engineering (MBSE) reaches its full value when architecture does more than describe a system. It should help engineers carry stakeholder need and system intent into executable analysis, preserve the configuration and criteria used, and return evidence that can be reviewed in the same architecture context. This dissertation develops and evaluates a seven phase, architecture-driven verification and validation framework for that purpose. The framework defines the responsibilities that connect SysML architecture, controlled execution, domain simulation, configuration management, persistent data, analytics, and accountable engineering review. A reusable Cameo/SysML digital test environment plugin provides the reference implementation for orchestration and model …