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Articles 61 - 90 of 1700
Full-Text Articles in Mechanical Engineering
An Approach To Expanding The Industrial Training And Assessment Center To The Residential Sector, Cailee Addison Bush
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 …
Interactions Between Different Deformation Mechanisms In Magnesium, Ethan T. Holder
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
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 …
Development Of A 3-Dof Contactless Magnetic Joint Actuator, Elle Whitney
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 …
Alternative Robust Design Formulation And Exploration Strategies For Managing Uncertainties In The Realization Of Complex Engineering Systems, Pooja Mukundan
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 …
Autonomous Defect Detection In Additive Manufacturing, John Samuel Poindexter Iv
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 …
The Prototype Of A Fully Automated Pressuremeter For Various Geotechnical Applications, Anuar Akchurin
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 …
Advancing Precision And Autonomy In Agriculture And Medical Imaging Through Ai And Computer Visions, Tan-Hanh Pham
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 …
Vibration-Based Algorithm For Diagnostic And Prognostic Condition Monitoring Of Railroad Bearings And Wheels, Jeffery Ray Pams
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
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
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.
Co-Designing Manufacturing Systems For Robustness And Resilience: A Decision-Based Design Perspective, Mathew Baby
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 …
Tracing Wave Induced Flow Field Surrounding Reef Balls, Alexis Scheele
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
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.
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 …
Experimental And Theoretical Fracture Analysis Of Additively Manufactured Orthotropic V-Notches, Venkata Siva Sainath Bavapuram
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 …
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 …
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
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
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, …
Digital Twins For Flexible Manufacturing, Drew Brandon Sander
Digital Twins For Flexible Manufacturing, Drew Brandon Sander
Theses and Dissertations
With the establishment of Digital Twins as an enabling technology for Industry 4.0, it is time to transition from the previous foundations to works that implement and highlight the capabilities Digital Twins present. The Industry 4.0 paradigm has recentered the focus on customizability, leading to reemerging goals of flexibility within manufacturing. Empowered through new cyber-physical systems, new enabling technologies are driving the revolution. To identify how Digital Twins as an enabling technology contribute to flexibility within manufacturing, a comprehensive investigation is conducted along with a detailed case study. A systematic literature review is conducted to analyze quality Digital Twin implementations …
Novel Redox Oxygen Active Materials For Solid Oxide Cells And Thermochemical Hydrogen Production, Jiaxin Lu
Novel Redox Oxygen Active Materials For Solid Oxide Cells And Thermochemical Hydrogen Production, Jiaxin Lu
Theses and Dissertations
This dissertation investigates novel materials designed to significantly enhance the performance and durability of oxygen electrodes for solid oxide cells and redox active materials for thermochemical hydrogen production. The first part of this work evaluates Ta-doped BaCoO₃₋δ (BCT) and its structural analog SrCoO₃₋δ (SCT), focusing on their catalytic performance in oxygen reduction and evolution reactions. Among BCT compositions (x = 0.1, 0.3, 0.5), the BCT10 (x = 0.1) composition exhibited the highest oxygen vacancy concentration, electronic conductivity, and lowest polarization resistance. However, SCT10 surpassed BCT10 in these critical performance parameters and also demonstrated greater stability over extended operational periods. Notably, …
Advanced Air Preheater Sealing Systems For Enhanced Efficiency And Reliability In Thermal Power Plants, Pavan Kumar Ravulaparthy
Advanced Air Preheater Sealing Systems For Enhanced Efficiency And Reliability In Thermal Power Plants, Pavan Kumar Ravulaparthy
Theses and Dissertations
Global electricity generation still relies heavily on thermal power plants, which consume vast amounts of fuel and emit significant amounts of carbon dioxide. A major but often overlooked source of inefficiency in these plants lies within the rotary regenerative air preheater (RAPH), a critical heat-exchange component where air leakage can exceed 20% in aging units. This leakage increases fuel consumption, parasitic fan power, and CO₂ emissions, while degrading boiler reliability.
This research introduces advanced adaptive sealing systems designed to mitigate these losses by dynamically compensating for rotor eccentricity, thermal distortion, and wear under harsh operating conditions. Brush seals, composed of …
Implementation Of Quantized Artificial Neural Networks With Spintronic Stochastic Computing, Saadi Sabyasachi Mr.
Implementation Of Quantized Artificial Neural Networks With Spintronic Stochastic Computing, Saadi Sabyasachi Mr.
Theses and Dissertations
Artificial intelligence or machine learning is going through a rapid expansion. It also incurs significant costs for power and device footprints. Various approaches are being explored to design energy and hardware efficient machine learning models. Stochastic computing has been proposed for efficient machine learning implementation. It requires a source of random number generation which poses some practical challenges. So spintronic solutions such as magnetic tunnel junction has been used for random number generation. Again, spintronic random number generation to implement high precision circuit is prone to device-to-device variations. Hence we designed quantized artificial neural network with spintronic stochastic computing which …
Online Parameter Adaptation Of Lqr Controllers Via Rls For Prosthetic Joint Control: Experimental Validation On A Quanser Qube-Servo 2 Platform, Cynthia Lopez-Jordan
Online Parameter Adaptation Of Lqr Controllers Via Rls For Prosthetic Joint Control: Experimental Validation On A Quanser Qube-Servo 2 Platform, Cynthia Lopez-Jordan
Theses and Dissertations
This thesis develops and experimentally validates an online adaptive Linear Quadratic Regulator (LQR) control method for prosthetic joint systems using Recursive Least Squares (RLS)-based real-time parameter estimation on the Quanser QUBE-Servo 2 platform. Traditional LQR controllers assume a fxed system model, which limits adaptability and results in reduced tracking accuracy, poor robustness, and loss of optimal performance when applied to dynamically changing prosthetic joints, infuenced by load variations, user gait changes, and mechanical wear. Limited experimental validation exists for combining RLS with online LQR adaptation in prosthetic-like systems.
To address these limitations, an RLS-driven Adaptive LQR framework was implemented to …
End-To-End Autonomous Quadcopter Using Reinforcement Learning, Mohamed Marwan Chawa
End-To-End Autonomous Quadcopter Using Reinforcement Learning, Mohamed Marwan Chawa
Theses and Dissertations
This thesis investigates the potential of Reinforcement Learning (RL) for achieving robust and adaptable quadcopter control, focusing on trajectory and attitude stabilization. We compare state-of-the-art RL algorithms, specifically Proximal Policy Optimization (PPO), against traditional Proportional-Integral-Derivative (PID) controllers across three tasks: hovering, slow trajectory following, and fast trajectory following. To enhance realism, we employ a modified PyFlyt simulation environment with a high-fidelity Crazyflie 2.x model, accounting for motor dynamics, noise, wind disturbances, and aerodynamic drag.
The challenge of operating a quadcopter can be divided into two distinct parts: planning a flight path and actually following that path. Our focus is on …
Crystal Plasticity Modeling To Capture Microstructural Variations In Cold-Sprayed Materials, Aulora Gail Williams
Crystal Plasticity Modeling To Capture Microstructural Variations In Cold-Sprayed Materials, Aulora Gail Williams
Theses and Dissertations
The high-velocity impact of powder particles in cold-spray additively manufactured (CSAM) parts creates intersplat boundaries with regions of high dislocation densities and sub-grain structures. Upon microstructure and mechanical characterization, CSAM Aluminum 6061 showed non-uniformity, with spatial variation in the microstructure and mechanical properties affecting the overall response of the additively manufactured parts. Post-processing treatments are conducted in as-printed samples to improve particle bonding, relieve residual stresses, and improve mechanical properties. In this work, we attempt to implement the effects of grain size and distribution of smaller grains along the intersplat boundaries using the grain size distribution function and powder size …
Experimental And Numerical Investigation Of Phase Change Material Melting Cycle In Microgravity, Ethan Michael Schuetzle
Experimental And Numerical Investigation Of Phase Change Material Melting Cycle In Microgravity, Ethan Michael Schuetzle
Theses and Dissertations
Efficient thermal management of spacecraft systems is crucial to overcome the extreme thermal conditions in space. Phase change materials (PCMs) offer significant advantages in thermal energy storage (TES) systems due to their high latent heat of fusion, the amount of energy stored or released during phase transitions. However, PCMs face limitations due to low thermal conductivity, especially in microgravity where heat transfer is primarily through conduction. This research addresses this issue by incorporating a 3D-printed aluminum lattice structure to enhance heat transfer to PCMs. Experimental data from sub-orbital flight tests and ground-based experiments, coupled with numerical simulations, are used to …