Mechanical Engineering Commons^™

Database Development For Reliable Small Object Detection In Maritime Environments, Jacob Matthew Whisenant

Theses and Dissertations

Achieving high reliability in small object detection is critical for advancing maritime and littoral intelligent navigation operations. Computer vision provides an undetectable form of perception that can be easily integrated into existing camera systems, offering a low-profile yet powerful solution for navigation and situational awareness in water-based environments. While deep learning techniques have significantly advanced the field of computer vision, the detection of small objects remains a persistent challenge. Limited pixel representation, the scarcity of large-scale small object datasets, and the reduced detail and indistinct features of small objects complicate detection efforts, especially in complex environments. These factors collectively hinder …

Informing Cold Spray Via High Strain Rate Particle Impacts Captured Using Ultra-High-Speed Videography, Elias Timmons

Theses and Dissertations

The primary objective of this research is to provide insight into high strain rate deformation behavior of particles in cold spray-like impacts for the purposes of material vetting and optimization of spray parameters for deposition quality and efficiency. A light gas gun and ultra-high-speed videography techniques were engineered, built, and used for millimeter particle impact experiments and adapted to launch micron scale particles at controlled velocities and particle/substrate temperatures representative of cold spray conditions. Analytical techniques employed for understanding impact mechanics focused on characterization of impact behavior and presence of features related to cold spray particle bonding. This research demonstrates …

Simulations Of Single Metallic Particle Impacts Onto Polymeric Substrates For Insights Into Cold Spray Adhesion At Composite Material Interfaces, Saidur Rahman Shoaib

Theses and Dissertations

Metallization of polymer-based composites finds applications in a variety of industries in which addressing challenges such as electrical discharge mitigation or surface erosion can be vital. Cold spray additive manufacturing is emerging as a cutting-edge technology for polymer/composite metallization, offering a transformative approach to achieving desired material enhancements. This study employs finite element analysis (FEA) to evaluate the adhesive “bonding” strength (i.e., extraction force under impulsive dynamic loading) between single 20-micron diameter spherical metal (copper) particles and polymer (polyetheretherketone) substrates under cold spray-relevant impact conditions. Analysis of FEA simulations centers on initial impact processes parameterized by particle impact velocity and …

Design And Control Of A Versatile Modular Soft Robotic System With Integrated Resource Sharing And Self-Reconfiguration Capabilities, Joshua Knospler

Theses and Dissertations

Modular, self‑reconfigurable soft robots promise unprecedented versatility by combining the compliance of soft materials with the adaptability of modular architectures. This thesis presents an integrated system of pneumatic, bending-type soft actuator modules. Modules are compact and fully equipped with tunable magnetic and electromechanical connections for low‑power attachment and detachment and a novel power-air-communication (PAC) connector for seamless sharing of electricity, compressed air, and digital signals. This work examines two representative assemblies: ManusBot, a pinching gripper, and TendrilBot, a versatile linear configuration for various tasks. Their grasping performance, variable stiffness, and radial support capabilities are characterized. A magnetic interlock and an …

Fused-Silica Microelectromechanical Systems For Relative Gravimetry, Ethan Doerstling

Theses and Dissertations

Gravimeters are devices that measure gravitational acceleration which can be used by the United States Air Force (USAF) in the areas of navigation and remote sensing. Fused-silica microelectromechanical systems (MEMS) devices offer capabilities to make inexpensive relative gravimeters with higher thermal stability than common silicon devices while maintaining good gravitational sensitivity. The fused-silica devices in this research were designed, simulated, fabricated, and tested to observe their performance as gravimeters. The devices exhibit properties of highly sensitive accelerometers but the current designs do not qualify as gravimeters. This study provides information to improve the sensitivity and stability of these fused-silica MEMS …

Experimental Characterisation Of Laser Cladding Of Crniw And Crnifealzr Powders On H13 Tool Steel And Optimisation Of Process Parameters, Martin Vinoth S

Theses and Dissertations

In this work, laser cladding on H13 steel substrate with two different powder compositions CrNiW and CrNiFeAlZr has been carried out. The laser power, powder feed rate, and scanning speed were varied and the clad dimensions, aspect ratio, and dilution percentage were measured. The microhardness found in the CrNiW clad is 834 ± 20 HV0.5, which is higher than that of the CrNiFeAlZr clad (780 ± 20 HV0.5) as well as the substrate (548 ± 20 HV0.5).

The X-ray Diffraction (XRD) patterns identified the common phase creation of Ni3C and Fe3C for CrNiFeAlZr and CrNiW coatings, while the oxide formation …

An Approach To Expanding The Industrial Training And Assessment Center To The Residential Sector, Cailee Addison Bush

Theses and Dissertations

The Industrial Training and Assessment Center (ITAC) conducts no-cost energy audits for small and medium sized industrial and commercial buildings across the United States, with a goal to train students in energy optimization and cost reduction, while helping companies to reduce inefficiencies and waste. Expanding this program to the residential sector can reduce energy usage across the United States, largely due to this sector contributing to 15% of America’s energy usage. This research examines the development of a procedure to transition the ITAC into including the residential sector. To ensure a seamless introduction of this sector, the procedure must contain …

A Rapid Artificial Neural Network Interatomic Potential For Bismuth, Lee Michael Mayfield Jr.

Theses and Dissertations

To study molecular dynamics in bismuth, Quantum Espresso was used to create a density functional theory (DFT) database which was then used as the input for rapid artificial neural network (RANN). The RANN interatomic potential that was developed using this database was then validated. Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) was used to create simulations and gather data using the RANN potential. The properties of bismuth, including elastic constants, melting points, and volume change, were calculated and compared to DFT and experimentally observed data. The RANN potential coincided well with these values. The RANN potential shows good predictive capabilities for …

Interactions Between Different Deformation Mechanisms In Magnesium, Ethan T. Holder

Theses and Dissertations

Magnesium is a strong and lightweight material with the potential to be used for weight reduction in various industries. However, manufacturing magnesium parts is difficult because magnesium is brittle at room temperature. Understanding the underlying deformation mechanisms in magnesium is critical to improving its ductility. In this work a Rapid Artificial Neural Network (RANN) potential was used to perform a Molecular Dynamics (MD) simulation in Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) to study twin formation and growth as well as interactions between different twin modes in a magnesium bicrystal. This work offers insight into the mechanisms of plastic deformation in …

Finite Element Analysis Of Hydroxyapatite (Ha) Coated Porous We43 Magnesium Scaffolds For Simulating Long-Time In Vitro Degradation Using A Continuum Damage Model, Dam Kim

Theses and Dissertations

While magnesium and its alloys are viable biodegradable implant candidates for its similarity of Young’s modulus with human bone and its strong biocompatibility, a pure magnesium scaffold degrades too rapidly to be used in many orthopedic implications. Overcoming this high degradation rate has been one of the biggest technical challenges for Mg-based biomedical applications. This research focuses on validating a finite element analysis framework using a continuum damage model and its application to simulate the degradation process of non-coated additively manufactured WE43 and HA-coated WE43 magnesium scaffolds. This work includes determining model input parameters by matching in vitro experiment results …

Atomistic Modeling Of Mg And Al Systems Using Rapid Artificial Neural Network Derived Interatomic Potential, Edward Omozusi Obasuyi

Theses and Dissertations

Machine learning derived interatomic potentials have proven to be effective tools in simulation that mimic the accuracy of ab-initio calculations to the sub meV/atom level. They offer the advantage of computational speed operating at linear scaling with respect to the system’s size making them more efficient than classical potentials like MEAM (modified embedded atom methods). In this work, interatomic potentials are created based on the rapid artificial neural network (RANN) formalism for magnesium (Mg), Aluminum (Al) and their alloys. From previous works, the RANN formalism produces high-fidelity atomic models with accurate force fields for several metals, offering new insights into …

An Updated Viscoplastic Self-Consistent Model To Capture The Effects Of Residual Stress, Microstructural Heterogeneity, And Precipitation In Cold-Sprayed Aluminum Alloys, Aulora Williams

Theses and Dissertations

Cold spray additively manufactured (CSAM) aluminum alloys exhibit heterogenous microstructures and mechanical properties, primarily due to high dislocation densities, sub-grain structures, and variation in inter-particle (intersplat) bonding arising from high-velocity particle impacts. Thermal post-processing has been shown to enhance intersplat bonding, reduce high residual stress concentrations, and lower dislocation densities, thereby improving the overall mechanical properties. Building on previous advancements with a mean-field viscoplastic self-consistent (VPSC) model, integrating intersplat boundary terms, Hall-Petch relations, and physically informed residual stress parameters, the current work extends the model to include precipitates and their effects. Observations of CSAM aluminum 7050 alloy indicate precipitate congregation …

Vibration-Based Algorithm For Diagnostic And Prognostic Condition Monitoring Of Railroad Bearings And Wheels, Jeffery Ray Pams

Theses and Dissertations

Bearing and wheel failure accounts for the majority of equipment-related train derailments on US railroads. Current wayside monitoring systems have been insufficient in the prevention of catastrophic derailments prompting the rail industry to explore the possible integration of onboard condition monitoring systems into their rail operations. The University Transportation Center for Railway Safety (UTCRS) in partnership with Hum Industrial Technology, Inc., has developed a wireless onboard system intended for the condition monitoring of railroad bearings and wheels. This thesis presents the development, evaluation, and implementation of an algorithm designed to be used in conjunction with these systems to provide railroad …

Analysis And Modeling Of Porous Media Networks In Petroleum Reservoirs Through Microscale Thermography And Core Flooding, Alan Petrovich-Mar

Theses and Dissertations

Reservoir rocks are porous materials that are an important area of study since they are present in reservoir sites rich in crude oil. It is important to understand the spreading phenomena on the rock surface and through the porous structure during fluid flow through these porous materials. For a complex system like reservoir rocks, factors such as spatially varying chemical composition and topography, multidimensional porosity, temperature, humidity, and existing oil/water in the pores can affect wettability and be a detriment to oil recovery.

The interaction of core samples with different porosity and permeability with water after proper cleaning procedures and …

Development And Tribological Characterization Of Uhmwpe-Tin Composite Coatings Deposited By Electrostatic Spraying, Jarrod Keith Perez

Theses and Dissertations

The increasing demand for inert, wear-resistant, cost-efficient, environmentally friendly, and low-friction coatings has driven extensive research into polymer-based solutions. Among these, ultra-high-molecular-weight polyethylene (UHMWPE) has emerged as a strong candidate due to its low density, anticorrosion properties, self-lubricating nature, affordability, and ease of processing. However, its low load-bearing capacity limits its widespread use in high-stress tribological applications. To overcome this limitation, this project investigates the development and characterization of UHMWPE composite coatings reinforced with titanium nitride (TiN) particles at varying concentrations (2.5, 5, and 10 wt%) to enhance their mechanical properties and wear resistance.

Fpso Motion In Synthetic Environments: Stereo-Driven Deep Learning For Wavefield Reconstruction, Motion Analysis, And Mooring System Assessment, Omar Jebari

Theses and Dissertations

This dissertation presents an integrated synthetic environment for simulating the motion and monitoring the integrity of a moored Floating Production Storage and Offloading (FPSO) vessel. The central hypothesis is that synthetic data-driven approaches can (1) accurately estimate spatio-temporal wave fields, (2) predict vessel motion, and (3) monitor the integrity of the mooring system—using stereo imagery of the wave field and structure motion, both of which can be acquired in real time. The first study develops a synthetic framework for estimating spatial wave fields using stereo images captured by dual cameras mounted on a moving FPSO. Dynamic sea states and vessel …

Tracing Wave Induced Flow Field Surrounding Reef Balls, Alexis Scheele

Theses and Dissertations

This study aims to explore the wave-induced flow dynamics around Reef Ball models using dye tracing techniques. Reef Balls are hemispherical artificial reefs with a hollow center and cavities throughout each face, they are designed in this manner to enhance coral reef restoration. Reef Balls rely on wave energy and current motion to facilitate water circulation and nutrient exchange within and surrounding their structure. To understand how wave action influences flow patterns around these artificial reefs, a scaled model experiment was designed to simulate real-world conditions. The experiments were conducted in the wave flume at Florida Institute of Technology’s Surf …

Tribological Characterization Of Laser Microtextured Ti-6al-4v Eli Alloy For Biomedical Applications, Nicholas Ricardo Perez

Theses and Dissertations

Titanium alloys have been gaining popularity in multiple fields due to their impressive physical properties, but struggle with poor tribological performance. This thesis aims to mitigate the poor tribological performance of titanium alloys through a laser microtexturing process. Ti-6Al-4V ELI (Extra Low Interstitial) alloy disks were evaluated against ultrahigh molecular weight polyethylene (UHMWPE) and polyether ether ketone (PEEK) pins. Four texturing patterns were created by changing the texture area fraction from 5 to 20% that were evaluated against untextured control samples. The tribological properties of the laser textured Ti-6Al-4V ELI disks were determined using a pin-on-disk tribometer under lubricated sliding …

Low Speed Water Tunnel Flow Testing, Humberto Cesar Grimaldo Jr.

Theses and Dissertations

Water tunnels serve as controlled environments for simulating fluid dynamics, providing an essential platform for studying flow patterns for hydrodynamic effects. This report presents a comprehensive overview and refurbishment of the water tunnel system located at the University of Texas Rio Grande Valley, focusing on its design, operation, calibration, and visualization capabilities for fluid dynamics research. The water tunnel, originally installed in 1995, was restored and updated with structural repairs, including resolving persistent leaks and implementing an improved drain system. A calibration process using a pitot tube and differential pressure transducer was conducted to establish accurate relationships between flow velocity …

Advancing Precision And Autonomy In Agriculture And Medical Imaging Through Ai And Computer Visions, Tan-Hanh Pham

Theses and Dissertations

Deep learning has revolutionized numerous fields by enhancing precision, automation, and decision-making capabilities. This dissertation explores its applications in agriculture and medical image processing, introducing novel methodologies to improve accuracy and efficiency in these domains. These fields hold critical societal importance -- agriculture underpins global food security and sustainability, while medical imaging drives advancements in diagnostics and personalized healthcare, both benefiting significantly from data-driven innovations. In agriculture, deep learning is applied to precision spray systems through droplet analysis. Specifically, a generative model is designed to create synthetic droplet images, addressing the challenge of limited training samples, which are expensive …

The Prototype Of A Fully Automated Pressuremeter For Various Geotechnical Applications, Anuar Akchurin

Theses and Dissertations

The geotechnical engineering field requires high-quality in-situ testing equipment that ensures consistency in the test execution. This research focuses on developing and testing a prototype of a fully automated pressuremeter control unit to allow the industry to obtain reliable and controlled stress-strain data, thereby improving efficiency and reducing testing time.

The objectives of this work are to design and develop a system with the necessary components to perform the pressuremeter test, integrate the testing procedure into the state machine design, enable automated testing, and validate the results by comparing the stress-strain data with that obtained from the existing hand-operated pressuremeter …

Alternative Robust Design Formulation And Exploration Strategies For Managing Uncertainties In The Realization Of Complex Engineering Systems, Pooja Mukundan

Theses and Dissertations

The design of complex engineered systems often relies on simulation-based models, which inherently introduce uncertainties. Managing these uncertainties is critical to ensure robust system performance. From a decision-based design (DBD) perspective, robust design metrics such as the Design Capability Index (DCI) and Error Margin Index (EMI) are employed to formulate and solve problems under uncertainty. However, existing formulations of these metrics rely on first-order Taylor series approximations for variance estimation, which are often inadequate in the presence of highly nonlinear or multimodal performance functions.

This thesis proposes alternate formulations of DCI and EMI, which use the multiple-point method of variance …

Co-Designing Manufacturing Systems For Robustness And Resilience: A Decision-Based Design Perspective, Mathew Baby

Theses and Dissertations

Manufacturing systems (MSs) comprise various stakeholders associated with the manufacture and supply of products required by customers and are interrelated by the flow of materials and information. The interrelated stakeholders make system-specific decisions and stakeholder-specific decisions across multiple levels of a decision hierarchy to satisfy many conflicting system-specific and stakeholder-specific requirements that define system and stakeholder performances. Given the stakeholder interrelations and conflicting nature of system-specific and stakeholder-specific requirements, system and stakeholder performances are correlated and conflicting.

In the Industry 5.0 era, there is an increased emphasis on the creation and equitable distribution of value among all the stakeholders in …

Autonomous Defect Detection In Additive Manufacturing, John Samuel Poindexter Iv

Theses and Dissertations

Additive manufacturing (AM) is the process of creating a product by applying layers of material to build up to the final product. AM has revolutionized the field of manufacturing and has allowed more complex products to be manufactured at reasonable cost, quicker manufacturing time, and optimized material usage. Traditional forms of manufacturing were based on subtractive manufacturing, where by a product would be created by removing material from its source. AM is a new manufacturing process and faces significant challenges when it comes to manufacturing due to defects. Defects can vary from type and severity and can overall weaken or …

Experimental And Theoretical Fracture Analysis Of Additively Manufactured Orthotropic V-Notches, Venkata Siva Sainath Bavapuram

Theses and Dissertations

This study presents a comprehensive investigation into the fracture behavior of additively manufactured orthotropic V-notched components made of Acrylonitrile Butadiene Styrene (ABS) material. The research integrates both theoretical and finite element approaches to evaluate stress intensity factors (SIFs) in Modes-I and II, which are fundamental in characterizing stress field distributions around notches under applied loading conditions. Unlike isotropic materials, where stress fields depend only on geometry of the component, the anisotropic nature of 3D-printed ABS introduces a dependency on material properties that necessitate different approaches to include anisotropy of the material.

Tensile specimens are 3D-printed with specific material orientations to …

Development Of A 3-Dof Contactless Magnetic Joint Actuator, Elle Whitney

Theses and Dissertations

The magnetic joint actuator is a relatively recent research technology that expands on the brushless DC motor to encompass rotation in three degrees-of-freedom. These actuators involve a stator with a series of electromagnetic coils oriented normal to a spherical permanent magnet rotor which can be controlled by modulating the current of the stator coils. The development of a magnetic joint actuator that operates without a physical connection between the stator and the rotor has wide applications for robotics in dust-sensitive environments, where a device with bearings would otherwise falter. This work details the design, sensing, and control of such a …

Automated Fiber Placement Laminate Level Optimization: A Physics-Inspired Method To Analyze Through-Thickness Defect Interactions, Nishan Patel

Theses and Dissertations

With the growing adoption of composite materials in industries such as aerospace, automotive, naval, wind energy, and even sectors like sports and consumer goods, there has been a strong push towards improving manufacturing reliability and productivity. One key method that has gained significant traction is Automated Fiber Placement (AFP), an additive manufacturing technique valued for its precision, efficiency, and adaptability in producing complex composite parts. As industries continue to shift from traditional metal-based structures to more advanced composite materials, the need for efficient and high- quality manufacturing solutions has become even more critical, prompting a focus on automation and optimization …

Explainable And Reduced-Feature Machine Learning Models For Shape And Drag Prediction Of A Freely Moving Drop In The Sub-Critical Weber Number Regime, Md Amanullah Kabir Tonmoy

Theses and Dissertations

Accurately predicting the shape and drag of a moving drop is crucial in many spray applications. However, due to the complex interaction between the drag force and drop shape deformation, accurate prediction of drop shape and drag from Computational Fluid Dynamics (CFD) simulation requires large computational resources and time. A novel data-driven approach using NARXNN (Non-linear Auto Regressive eXogenous input Neural Network) is proposed in this study, which recurrently predicts the drop shape and drag for a given Weber number (We) and Reynolds number (Re), in the sub-critical We regime where there is no drop breakup. The average error in …

Frequency-Based Rapid Structural Damage Detection Using Embedded Edge Computing On Resource-Constrained Devices, Ryan Yount

Theses and Dissertations

Structural Health Monitoring (SHM) is essential for ensuring reliability and longevity of useful structures. Traditional SHM approaches rely on manual or remote data transmission and external processing, which introduce latency and can depend on stable communication links. This work aims to advance SHM by integrating edge-computing techniques for rapid damage detection to enable faster and more autonomous structural assessments in resource-constrained environments. The research spans three key contributions including 1) frequency-based damage detection of civil structures using a sensor package with the addition of an edge processor, 2) additions to the computational efficiency of the edge-computing sensor package in a …

Improvement Of Microcracking And Mechanical Properties Of Tungsten Fabricated Via Laser Powder Bed Fusion Through Alloying With Reactive Secondary Constituents, William S. Mockel

Theses and Dissertations

Tungsten (W), a Group VI transition metal, possesses a number of advantageous properties, most notably its impressive mechanical performance at extreme temperatures. While tungsten's nature render traditional manufacturing methods difficult, additive manufacturing through laser powder bed fusion (LPBF) presents a promising avenue for fabricating tungsten components. However, the material’s high ductile-to-brittle transition temperature combined with the embrittling effect of impurities mean that the residual stresses imparted by LPBF result in microcracking in tungsten, degrading its usefulness. This study sought to improve the characteristics of LPBF-W through the removal of embrittling oxygen content via alloying with low concentrations of reactive elements, …