Mechanical Engineering Commons^™

Advancing Additive Manufacturing For Extreme Environments Through Simulated Microgravity Printing, Laura Nayeli Molina

Open Access Theses & Dissertations

Additive Manufacturing (AM) holds significant potential for space exploration by enabling on-demand fabrication of components, reducing payload costs, and enhancing mission adaptability. However, microgravity introduces challenges in thermal regulation, material deposition, and structural integrity. This research explores the feasibility of submerged AM using neutral buoyancy in silicone oil to simulate microgravity conditions on Earth. A 3D printer was modified for submerged operation, with samples printed under three conditions: no oil (ambient air), submerged in oil, and simulated microgravity at varying temperatures. Mechanical tests, fracture surface analysis, and density measurements were performed to evaluate tensile strength, surface adhesion, and dimensional stability. …

Tailoring Functional And Sensing Properties Of Polymer-Ceramic Composites Via 3d Printing, Alexis Lopez

Open Access Theses & Dissertations

Section 1.1. Abstract This chapter investigates the use of direct ink write (DIW) additive manufacturing to control grain orientation in non-toxic barium titanate (BTO) ceramics by blending spherical and platelet-shaped particles in the ink. A series of inks containing 0–40 wt.% BTO platelets were formulated with poly(vinyl alcohol), polyethylene glycol, poly(acrylic acid-co-maleic acid), and ammonium hydroxide to ensure printability and homogeneous dispersion. Cylindrical specimens (20 mm × 3 mm) were printed using a Hyrel 30M DIW system and subjected to de-binding (650 °C, 2 h) followed by a two-step sintering schedule (T₁: 1200–1350 °C; T₂: 700–850 °C; 24 h dwell). …

De Novo Design Of Ablative Polymers For Aerospace Thermal Protection Systems Through An Integrated Ai-Theory-Experiment Approach, Rene Damaso Boisseau

Open Access Theses & Dissertations

Novolac phenolic resin (NPR) is a widely used polymeric ablative material (PAM) for thermal protection systems (TPS) due to its high thermal decomposition temperature (TD, 500â?¯Â°C) and char yield (YC, 55â?¯wt%). However, its drawbacks (including high thermal conductivity, low mechanical properties and water uptake) prompt the need for improved PAMs. This study explores the pyrolysis behavior and char-forming capabilities of NPR and a potential alternative PAM, poly(1,6-dimethyl phenol) (PPO), through both theoretical and experimental approaches. A graph neural network (GNN) was developed to predict structure-property relationships, revealing that benzyl group positioning and oxygen atom placement significantly influence YC. PPO's para-positioned …

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 …

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 …

Advanced Porosity Control Of Cp780 Galvanized Steel During Gas Metal Arc Welding With Pulsed Arc, Carlos Adrián García Ochoa, Jorge Alejandro Verduzco Martínez, Francisco Fernando Curiel-López, Víctor Hugo López-Morelos, Jaime Taha-Tijerina, Ariosto Medina Flores, Maleni García Gómez

Informatics and Engineering Systems Faculty Publications

This study investigated the control of porosity during gas metal arc welding with pulsed arc (GMAW-P) of complex-phase 780 (CP780) galvanized steel. Due to the Zn coating on this type of steel, porosity forms during welding as a result of Zn vaporization. The objective was to optimize the welding parameters to minimize porosity with a design of experiments using an L9 orthogonal array to analyze the effects of peak current (Ip), pulse time (tp), and pulse frequency (f) in high-speed welding conditions. The results showed that porosity was significantly reduced with a peak current of 313 A, a frequency of …

Manipulating Martensitic Transformation And Residual Stress Development In Stress Superposed Incremental Forming Of Ss304, Elizabeth M. Mamros, Fabian Maaß, Thomas Gnaupel-Herold, A. Erman Tekkaya, Brad L. Kinsey, Jinjin Ha

Faculty Journal Articles

Stress superposition is one of the strategies used in metal deformation processes to increase the material formability, decrease the required forming forces, and create highly customized components. To investigate the effects of tensile and compressive stresses superposed to the single point incremental forming (SPIF) process, experiments and numerical simulations were conducted for a stainless steel 304 (SS304) truncated square pyramid geometry. Tensile stresses were superposed in-plane on the specimen blank by a custom hydraulic frame, and compressive stresses were incorporated via a polyurethane die. Identified parameters for a martensitic transformation kinetics model for SS304 were used in a two-step finite …

Quantifying The Threshold For Fragmentation Of Newtonian And Non-Newtonian Drops, Aditya Parik

All Graduate Theses and Dissertations, Fall 2023 to Present

This dissertation investigates how the properties of liquid drops influence the minimum aerodynamic forces needed to cause the drop to fragment (breakup). For this work, we focus only on aerodynamic forces that are applied on a stationary drop by a sudden, uniform flow, a process called impulsive acceleration. Previous studies have largely focused on the fragmentation of spherical drops of Newtonian fluids (liquids with constant viscosity, like water), when impulsively accelerated in air-like ambient medium. Such systems only capture a limited range of drop and ambient properties (described by non-dimensional groups). Many real-world applications, such as aerial fire retardant delivery, …

Cruising On The Beach (Cob), Juan Diego Molina Ii, Ashley Kianna Burga

Biomedical Engineering

This report details the design and development process of Cruising on the Beach (COB), a modular motorized wheelchair intended to improve beach accessibility for high school students with mobility impairments. The project aimed to create an affordable, portable, and sand-capable device using balloon wheels, an adjustable control panel, and a customizable base. Extensive background research, market analysis, design modeling, and test plans were completed. However, final fabrication was not achieved due to financial constraints and limited access to industrial machining tools needed for custom metal components. Despite these setbacks, the project delivered a robust conceptual design and a fully …

Baja Sae Brakes, Carson Moore, Jaedyn Michael Imhoff, Will Duncan, Matthew Shaffer

Mechanical Engineering

Historically, the Cal Poly Racing Baja SAE has produced a braking system that has proven unreliable and barely passes competition rules and inspections, leading to ill performing and unsafe brakes. The goal of this project is to produce a system and documentation that meets the requirements provided by Cal Poly Racing Baja SAE. The final design includes a transient braking model of the vehicle to set system requirements, universal custom front and rear calipers modified from “Cal Poly BSAE Custom Brake Caliper Senior Project”, and a revamped hydraulic harness. Leaning on the team’s previous work and modifying the custom calipers …

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 …

Engineering Of Metallic Interpenetrating Phase Composites For The Control Of Deformation And Failure Modes During Dynamic Events, David Kiyoshi Santacruz

Open Access Theses & Dissertations

Aerospace components, automotive structures, and ballistics armor are all engineered to withstand high strain rate service events through a combination of material selection and design choices. However, structural components may be less effective when their implementation is constrained by other factors such as weight or design limitations. To meet these challenges, the development of next-generation materials will need to increasingly rely on composite material systems rather than monolithic materials. This thesis presents the fabrication, dynamic characterization testing, and post-mortem analysis of 316L/A356 interpenetrating phase composites (IPCs) made from the PrintCasting methodology. These composites consist of additively manufactured 316L stainless steel …

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 …

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 …

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 …

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 …

Bomb Calorimeter As Proof Of Concept For Low-Cost Calorimeter To Measure Thermal Runaway In Pouch Cells To Facilitate Statistical Characterization, Mykell Johnson

All Graduate Reports and Creative Projects, Fall 2023 to Present

Transportation is becoming increasingly electrified, with the main energy storage system being lithium-ion (li-ion) batteries. Despite the widespread adoption of li-ion batteries, unique design abuse tolerance concerns need to be addressed, specifically regarding the catastrophic exothermic release of energy, called thermal runaway (TR). While TR is a major design consideration in all li-ion applications, it presents unique difficulties in the electric aviation industry. The Federal Aviation Administration (FAA) considers thermal runaway inevitable in a battery pack and requires containment of the event per DO311-A for certified aircraft. Due to the wide variability of TR, designing for this phenomenon can be …

Deciphering And Translating Bioinspired Structures For Engineering Materials Design Via Computational Modeling And Machine Learning, Zhangke Yang

All Dissertations

Nature has evolved extraordinary structural materials—such as nacre, bone, and the mantis shrimp’s dactyl club—that achieve remarkable combinations of strength, toughness, and impact resistance. These properties arise from sophisticated synergies between structure and composition. Inspired by these biological systems, this dissertation presents a comprehensive investigation into bioinspired materials, uncovering fundamental mechanisms and providing guidance on designing materials with superior mechanical properties.

This dissertation begins by examining the "brick-and-mortar" structure of nacre, which informs the design of layered polymer-graphene nanocomposite films. Using coarse-grained molecular dynamics simulations, I elucidate mechanisms of dynamic wave propagation and energy dissipation in these systems, providing critical …

Wide Lock-In Energy Harvesting From Vortexinduced Vibrations Of A Deformable Cylinder, Ahmed Raafat Mostafa

Theses

Energy harvesting from ambient sources has gained attention due to increasing energy demands. Despite VIV-based harvesters showing significant potential, their lock-in region, where significant power is generated, is narrow. Given the continuously varying ambient conditions of fluid currents, harvesters can easily fall into de-synchronization, yielding low energy output. Existing solutions like tunable masses or multiple degrees of freedom systems increase complexity and weight, limiting practical applications. This work introduces a novel variable diameter cylinder mechanism—a practical technique that actively tunes the cylinder’s geometry in real time to enhance energy harvesting efficiency from VIV. The mechanism employs an expanding pulley system …

Graphics Processing Unit-Enabled Path Planning Based On Global Evolutionary Dynamic Programming And Local Genetic Algorithm Optimization, Junlin Ou, Ge Song, Yi Wang

Faculty Publications

This paper presents a novel path planning method for real-time robotic path planning in a dynamic environment involving moving obstacles. It combines on a holistic platform a global approach to rapidly generate initial paths of prominent diversity and a heuristic approach to enable local path refinement for enhanced computational efficiency, exploration, and robustness. The global approach innovates a formulation that treats a path planning problem with a visibility graph as a Markov decision process and decomposes the process into many subproblems. A new evolutionary dynamic programming approach (EDP) is proposed to solve these subproblems in an iterative manner using …

Quantifying Buoyancy-Driven Exchange Flows Over Obstacle At The Great Salt Lake Using Rans Cfd, Mohammad Ikram Hossain Talukdar

All Graduate Theses and Dissertations, Fall 2023 to Present

This study examines how barriers, such as berms, affect the movement of water in the Great Salt Lake in Utah. The lake experiences two types of water flow: one, called a unidirectional gravity current, where denser water flows in a single direction, and another, known as buoyancy-driven exchange flow, where water flows in two opposite directions due to differences in both water density and surface elevation. These flows are important for understanding how water mixes and moves between the northern and southern parts of the lake. Using computer models, we simulated how these two types of water flows behave when …

Dynamics Of Rotating 2d Ellipse In Stratified Flow, Anton G. Kadomtsev

All Graduate Theses and Dissertations, Fall 2023 to Present

Submersible vehicles that move through seawater are subjected to a variety of effects. Seawater has a non-uniform density because of uneven heating and the tendency of dense saltwater to sink. This non-uniform density distribution induced by gravity is known as stratification and introduces vertical confinement and internal gravity waves to flows around bodies. Along with translational motion, these vehicles also perform rotational motion. To identify the effects of density gradient, body shape, and rotation on the flow, 2D direct numerical simulations (DNS) are run and analyzed. The simulations are conducted using the open-source CFD solver Nek5000, utilizing its overset-grid-based methodology. …

Investigation Of Control Strategies For Swing-Up Maneuver Of A Double Inverted Pendulum On Rotating Link, Abdulrahman Mohammad Rahmani

Thesis/ Dissertation Defenses

This thesis is concerned with investigation of the swing-up control problem of underactuated mechanical systems namely the double rotary inverted pendulum using the optimal control theory. The research aims to develop a robust controller to achieve the swing-up and stabilization of the pendulum in the upright unstable equilibrium position while regulating the angular displacement of the rotating arm and the two pendulum angles. The performance of the designed controller was evaluated through numerical simulations in the MATLAB/Simulink environment. A comprehensive review of the literature was conducted and the challenges that researchers face in the control of underactuated mechanical systems were …

Campus Navigator: A Mobile App For Seamless University Navigation, Hafsa Mohammed, Ali Rahimzadehfard, Rachab Wilson, Mathias Rossi, Turaj Ashuri, Amir Ali Amiri Moghadam

Symposium of Student Scholars

Navigation services play a big role in everyone’s daily lives, from directing them on new roads to guiding them through buildings. Outdoor navigation services have evolved from physical maps to digital ones like Google Maps for ease of use and accessibility. Upon conducting literature research, the team found that many navigation apps lack clear and accurate instructions for how to navigate university campuses such as Marietta campus. Due to the size of KSU’s Marietta campus and its buildings, effortless navigation has been a common challenge for students, faculty, and visitors alike. Additionally, all buildings are referred to by letters, numbers, …

Low Cost Additive Manufacturing Of Segmented Stator Composite Polymer Permanent Magnet Dc Motors, Ben Goldberg, Jordan Bailey, Connor Hawkins, Colin Haskins, Razvan Voicu

Symposium of Student Scholars

This study presents a novel approach to the design, manufacture, and optimization of segmented stators for composite construction axial flux permanent magnet DC motors. Traditional axial flux stator manufacturing is both challenging and expensive, creating a bottleneck in rapid prototyping and innovation. To overcome these limitations, the stator is divided into individually fabricated segments using advanced composite polymer materials and low-cost additive manufacturing techniques. This segmentation not only drastically reduces production complexity and cost but also allows for customized coil geometries that maximize the surface area for improved heat dissipation.

A key innovation of our design is the integration of …

Building Resilience: Strategies For Sustainable Wildfire Management In California, Jaiden Rennie, Pegah Zamani

Symposium of Student Scholars

Wildfires in California are becoming more intense and destructive, threatening communities, ecosystems, and livelihoods. This project explores how resilience and sustainability can work together to reduce wildfire risks and long-term damage. By reviewing research, case studies, and expert insights, it examines what’s driving these fires, climate change, poor land management, and human activity, and looks at solutions that can make a real difference. From community education programs to AI-driven fire detection and smarter policies, the findings highlight practical ways to better prepare for and manage wildfires. The goal is to contribute to a future where communities and the environment are …

Cellulose Recovery From Waste Denim Fabrics Through Indigo Vat Dye Reduction And Spandex Dissolution, Tito N. Venance

Tanzania Journal of Engineering and Technology (TJET)

This study addresses environmental conservation by tackling end-of-life management for post-consumer denim garments through the recycling of cotton fibres from waste denim. The purification process involved dithionite reduction of vat dyes in the presence of an alkali followed by selective dissolution of spandex using N,N-dimethylformamide (DMF). Optimal conditions for dye removal were determined at 90°C for 120 minutes with sodium hydroxide at 25 g/L, sodium dithionite at 6 g/L and PVP at 4.5 g/L, while spandex extraction was achieved using a 5% DMF solution at 70°C for 4 hours. Ultraviolet (UV)-vis spectrophotometric analysis indicated a significant increase in whiteness (DL*). …