Engineering Commons^™

Non-Intrusive Reduced Order Model Formulation For Inverse Shape Design Including Deforming Meshes And Multiphysics Problems., Kapil Aryal

Mechanical and Aerospace Engineering Dissertations

Despite significant advancements in computer capabilities for numerical simulations, engineers continue to face limitations when dealing with large-scale full-order model(FOM) simulations. These simulations often necessitate repeated solves, such as those encountered in inverse design, real-time solution prediction, error quantification, and solver convergence, among others. To address these challenges, reduced order modeling (ROM) has emerged as a valuable approach. This thesis focuses on the development of an ROM framework that combines Proper Orthogonal Decomposition (POD) with machine learning techniques. This integrated approach is applied to a diverse range of heat transfer and fluid flow inverse design problems. POD constructs optimal sets …

Cooperative Manipulation And Formation Control Using Multiple Aerial Vehicles, Uluhan Cem Kaya

Mechanical and Aerospace Engineering Dissertations

Recent advancements in autonomous systems have significantly impacted both academia and industry, opening new research avenues. One of them is the collaboration of multiple systems to achieve a common goal, which is known as a cooperative system. In the lack of human intelligence, decision making and perception capabilities, uncrewed autonomous systems could mutually benefit from each other’s capabilities when they are deployed and utilized together. This research tackles the collaboration of group of uncrewed aerial systems (UASs) where the constraint on individual vehicles requires a varying level of coordination and cooperation. Such cooperation can be in the form of a …

Method-Of-Characteristics Models For Flowfield Evaluation Of Hypervelocity Test Facilities, Anannthkumar Jayamani

Mechanical and Aerospace Engineering Dissertations

Ground test facilities are an imperative part of the design and development of flying vehicles. In the case of high-enthalpy facilities, evaluating the gasdynamic and thermochemical state of the test gas poses challenges due to high temperature effects. This study aims to contribute to the development impulse facilities by developing reduced-order models resolving the flowfields of such facilities. Developed as a part of this study are various method-of-characteristics (MoC) algorithms which consider gases under varying levels of thermochemical complexity. The algorithms span from simple calorically perfect gases to full thermochemical nonequilibrium. The first set of algorithms was limited to unsteady …

Turbulent Shockwave/Boundary-Layer Interactions Generated By Sharp Swept Fins, Dustin Levi Otten

Mechanical and Aerospace Engineering Dissertations

The shock/turbulent boundary layer interaction (STBLI) generated by a sharp fin with a 60 deg leading edge sweep mounted above a flat plate at Mach 2.5 was studied numerically. Incipient separation due to this highly swept fin was determined by varying the fin angle to the incoming freestream. The effect of a small fin/plate gap on STBLI incipient separation was established. Sweeping the fin increases the deflection required for incipient separation as the sweep reduces the interaction strength. A gap causes flow leakage under the fin, further reducing the interaction strength on the windward side. The incipient angle of attack …

Cooperative Rendezvous In Multi-Vehicle Systems, Rajeev Shobhit Voleti

Mechanical and Aerospace Engineering Dissertations

The field of cooperative, multi-vehicle systems has witnessed a significant expansion and evolution, yielding considerable opportunities for improved autonomy, resilience, and robustness. Despite these promising developments, complex challenges persist in ensuring secure and efficient rendezvous among cooperative peers. The term "rendezvous," within the realm of cooperative control, refers to the simultaneous convergence of multi-vehicle systems to a designated target location. In missile guidance, the problem of multiple pursuer missiles achieving rendezvous with a target is termed as a salvo attack. Current methodologies often grapple with issues related to synchronization, high latency and network security, all of which can adversely impact …

Microstructural Finite Element Modeling Of High-Performance Carbon Fiber-Reinforced Composites To Characterize Microscale Material Properties And Fiber-Direction Compressive Strength, Quy Tung Ling Vu

Mechanical and Aerospace Engineering Dissertations

Carbon fiber-reinforced composites are increasingly used in aerospace application thanks to their excellent specific stiffness and strength. However, incomplete understanding of their failure behaviors leads to composite components often being designed with a high Safety Factor, limiting their advantages. Using computational methods, this project studies carbon fiber-reinforced composite microstructures for the objective of understanding and improving material performances under compression load which is one of the main considerations in primary aerospace structure design. A Finite Element (FE) model for the evaluation of composite compression behaviors was developed, allowing the identification of several key material properties affecting composite performance. The numerical …

Hitch Cart “Landing Gear”, Rebekah White, Jose Raygoza, Randy Hernandez, Brandon Leon

Mechanical Engineering

This report aims to allow our sponsor, to review our design process of the Hitch Cart Landing Gear Prototype. In the design overview section of this report, we discuss the primary design modifications we made to the wheel mechanism of the existing hitch cart prototype, including the addition of the ACME screws and the folding brackets. This allows our sponsor to see the intended improvements made to the past prototype and understand the primary goal of our project. Then, in the implementation section, we cover the entire manufacturing process to allow our sponsor to understand what manufacturing steps must be …

Development Of A High-Throughput Methodology For Vibration-Based Fatigue Tests, Brandon Alexander Furman

All Graduate Theses and Dissertations, Fall 2023 to Present

Global efforts towards the development of additively manufactured materials, biomaterials, metamaterials, self-healing materials, and composites have reached a staggering pace. With new materials being developed on a near-daily basis, it is more important than ever to be able to quickly and precisely quantify their mechanical performance. However, one of the most important mechanical properties, fatigue life, is notoriously time consuming to measure. Consequently, fatigue parameters are often calculated based on small sample sizes, resulting in high uncertainty of the measured parameters. In this dissertation a high-throughput approach to fatigue measurements is developed. This technique allows for multiple samples to accumulate …

Utilizing Bayesian Optimization In Technoeconomic Analyses For Integrated Energy Systems, Anthoney Griffith

All Graduate Theses and Dissertations, Fall 2023 to Present

Technoeconomic analysis is a key element in the study of integrated energy systems. The goal of this analysis is the sizing of technologies resulting in the best economic outcome for the system. The evaluation of this system involves sizing the components and simulating the resulting market to determine an outcome. This simulation incorporates multiple possible values of uncertain parameters like grid price and wind generation. This problem is currently approached with the gradient descent optimization method. An alternative approach, Bayesian optimization, sees success on simple problems of a similar nature to technoeconomic analyses. These results motivate applying Bayesian optimization as …

Study Of Polymer-On-Polymer Cold Spray Deposition Windows Under Apparently Similar Conditions, Ülar Tiitma

Theses and Dissertations

The purpose of this thesis is to explore and expand the capabilities of polymer-on-polymer cold spray demonstrated herein using polyamide 6 (PA6)-based powder and substrates. Experiments were conducted using three different cold spray systems described in this work, permitting more in-depth examination of process response to different cold spray process control parameters, such as nominal system pressure and temperature. Two specific responses of interest were the deposition window (DW) and deposition efficiency (DE) of PA6. The DW was determined by performing several sprays at different calculated particle impact velocities and temperatures. The composite result from these experiments was identification of …

Capstone Review: Filament Unit Multiplexing Engine, Gal Cohen

University Honors Theses

The Filament Unit Multiplexing Engine (FUME) is a Mechanical Engineering capstone project sponsored by Portland State University's Electronic Prototyping Lab (EPL). The project addresses the need for an automated system to manage 3D printing operations. The current manual process of selecting and routing a spool of filament to one of the available 3D printers is labor-intensive and limits the efficiency of the lab's 3D printing farm. FUME aims to create a custom solution tailored for a multi-user, multi-spool, and multi-printer environment. The designed system includes key components: a spool holder, an engine, a track and shuttle system, and a funnel. …

Shape Memory Alloy Capsule Micropump For Drug Delivery Applications, Youssef Mohamed Kotb

Theses and Dissertations

Implantable drug delivery devices have many benefits over traditional drug administration techniques and have attracted a lot of attention in recent years. By delivering the medication directly to the tissue, they enable the use of larger localized concentrations, enhancing the efficacy of the treatment. Passive-release drug delivery systems, one of the various ways to provide medication, are great inventions. However, they cannot dispense the medication on demand since they are nonprogrammable. Therefore, active actuators are more advantageous in delivery applications. Smart material actuators, however, have greatly increased in popularity for manufacturing wearable and implantable micropumps due to their high energy …

Barcode Medication Administration (Bmca): 2023-24, Krishan R. Patel, Carlos E. Sosa, Mary Grace Sy

Industrial and Manufacturing Engineering

The Barcode Medication Administration is an important system implemented within a hospital. It is the process in which nurses and other healthcare professionals prescribe and distribute medication to the patients. It aids in organizing which patient got prescribed which medication from which doctor and provides records on who was given care by who. The whole BCMA system is a multi-step process from getting the medication prescribed, to the nurses having to pick up the medication from the medication cabinet, and then having to scan the patient and the medication to finally administer medications.

The current BCMA system implemented at the …

Smart Manufacturing For Cal Poly's Ime Curriculum, Grace L. Guarraia, Eric F. Ledesma

Industrial and Manufacturing Engineering

California Polytechnic State University, San Luis Obispo (Cal Poly) takes pride of supporting one of the nation’s strongest undergraduate Industrial and Manufacturing Engineering programs. However, as industry evolves to accommodate advancing computing power, improved manufacturing algorithms, and improved robotics, it is imperative that Cal Poly’s curriculum evolves in parallel. Smart manufacturing is the future of the manufacturing industry, and Cal Poly is searching for the ideal method to teach and integrate Smart Manufacturing into its classes. With its upcoming switch to the semester system, coupled with its “Learn by Doing” motto, the department is at an ideal period for the …

Impact Force Helmet Device For Concussion Monitoring, Patrice Mulligan, Karina Mealey, Zack Borthwick, Benjamin Fick

General Engineering

To track head trauma in football, our device is placed inside a football helmet to measure both linear and gyroscopic (rotational) accelerations. These measurements are taken using an ADXL375 linear accelerometer and an LSM6DSOX accelerometer and gyroscope. The data from these sensors is processed and transmitted wirelessly by a SparkFun Thing Plus microcontroller to another SparkFun Thing Plus microcontroller connected to a laptop on the sidelines. Our program on the laptop stores the acceleration impact data into a .csv file for each player. If a likely concussive impact is detected, the program displays a popup warning. Testing results were promising …

Enhancing Miter Saw Safety: Challenges And Prospects Of Brake Incorporation With An Automatic Blade Retraction System, Derek Cole

University Honors Theses

Miter saws pose significant safety risks with thousands of injuries reported annually. Despite this risk, they are still used every day as they are a necessity for thousands of workers in the United States and globally. This leaves a demand to make these machines safer to mitigate any potential harm. This research addresses the critical need for an automatic safety system for miter saws, aiming to enhance user safety by retracting and stopping the blade upon skin contact. This analysis identified the primary challenge: The large force generated when braking at high speed on a miter saw blade, translates the …

Feasibility And Characterization Of Leak-Tight Single-Track Thin Walls Produced By Laser Powder Bed Fusion In 316l Stainless Steel, Peyton J. Archibald

Master's Theses

This thesis explores the optimization of process parameters for producing single-track thin walls using Laser Powder Bed Fusion (LPBF) additive manufacturing. Using two different coupon designs, the study assesses the feasibility of creating the thinnest possible leak-tight structures within LPBF and evaluating their mechanical properties, including burst pressure and modulus of elasticity under pressure loads. A series of experimental iterations were conducted, varying laser power and laser speed to identify optimal conditions. The findings indicate that a narrow range of process parameters can produce consistently leak-tight thin walls. The results contribute to understanding how to achieve high quality, reliable thin …

Impact Of Student Beliefs And Self-Efficacy On Performance In Higher Education Stem Courses, Lauren Nicole Fogg

Doctoral Dissertations

In engineering education, students often face feelings of inadequacy, leading to academic struggles and potential dropout. This dissertation investigates the impact of interactive course materials on students' confidence and self-efficacy in problem-solving, focusing on an Engineering Materials class at Louisiana Tech University. Over four quarters, involving seven sections and 218 students, a 13-question Likert scale survey was administered repeatedly, alongside demographic data and textbook usage surveys. The study aims to compare students’ attitudes and beliefs when not using a textbook versus when using an interactive web-native book. Hypotheses suggest that the interactive book will enhance problem-solving beliefs, confidence, and grades. …

Redesign Of Leg Assembly For Remote Walking Training Device To Improve Gait Kinematics, Jacob Anthony

Mechanical Engineering Theses

As modern medicine has improved, the average age of patients has increased. This has cause a growing number of patients to develop disabilities over time due to spinal cord injuries and stroke among other neurological ailments. This has led to an increased interest in developing robotic exoskeletons to help patients with neuromuscular rehabilitation. However, most exoskeletons do not accurately replicate the natural human gait kinematics due to a lack of degrees of freedom at the designed knee joint. In this thesis, the leg assembly for a robotic rehabilitation (RoboREHAB) device is redesigned to improve the gait kinematics and a reinforcement …

Recovery Of Cyber Manufacturing Systems From False Data Injection Attacks On Sensors By Reinforcement Learning, Romesh Prasad

Dissertations - ALL

Cyber-manufacturing systems (CMS) represent the future design vision for manufacturing systems, aiming to enhance product quality, and productivity, and reduce downtime. The third industrial revolution was driven by computer systems and automation, while the fourth industrial revolution was inspired by the internet, network, and connectivity. However, this integration also introduces vulnerabilities, particularly through false data injection attacks on sensors. Sensors play a pivotal role in the automation framework of manufacturing systems spanning five levels: process, operational, supervisory, plant, and enterprise. Sensors are instrumental in communicating information from the process level to the enterprise level. It also enables controllers at the …

Analyzing Heat Generated From Electro-Osmotic Flow Utilizing Computational Fluid Dynamics, Jordan Elizabeth Grothe

Honors Thesis

Without extensive vascularization, the transfer of fluid and nutrients through human tissue is limited to diffusion and weak interstitial flow. Electroosmosis, or the flow of fluid driven by an electrical field, has become a promising solution. Scientists have begun applying electricity to human tissue to promote stronger interstitial flow; however, optimization of this process has proven to be a challenge due to ohmic heating. Cells function within a small range of temperatures and exposure to voltages exceeding the threshold will cause cells to degrade and die prematurely. This research seeks to better understand and quantify the range of voltage where …

Application Of Biochar / Bentonite Based Admixtures In Reinforced Concrete For Corrosion Prevention, Jacob Fleury

Graduate Theses & Non-Theses

Reinforced concrete systems are in many sectors of infrastructure. Due to a combination of elevated compressive strength from the cement and aggregates and tensile strength from the reinforcing steel, reinforced systems are favorable in construction applications where high strength is desired. However, while reinforced concrete is in service, it can be introduced to contaminants that cause corrosion. Contaminants can leach through the porous matrix of the concrete structure and influence initiation of corrosion products on reinforcement. Corrosion is the primary cause for advanced deterioration of concrete structures. Concrete deterioration has promoted research efforts for the protection of future systems. This …

An Analysis Of Primary Stability Of Stemless Humeral Implants In Shoulder Arthroplasty, David Cunningham

Electronic Thesis and Dissertation Repository

There is a scarcity of literature on the performance of the stemless humeral components. This present work describes the development of a novel loading simulator for the quantification of implant performance, as well as its use in the evaluation of implant parametric design and surgical protocol decision variables.

Interface fixation of humeral components was first evaluated using computational methods to determine the optimal metric to quantify implant fixation. Distractive micromotion was found to be the defining micromotion direction in two different designs of humeral implants.

A loading simulator capable of replicating 3D physiological loads, and comprehensive loading and digital image …

Rasc-Al Large Scale Lunar Crater Prospector, Austin Arnold, Coleman Alvarez, Mark Suberu

Senior Design Project For Engineers

The purpose of this project is to design a conceptual layout of a lunar rover capable of exploring craters at the lunar south pole. The rover should be autonomous and capable of self-sustainment for at least one year in extreme cold and darkness. While determining the location and accessibility of water ice and other volatiles within the crater. This document will contain all information related to the team's conceptual design. Including research, component selection, electrical design, and mechanical design.

Lunar Rascals Video: https://www.youtube.com/watch?v=MdcjzVMtzaI

Novel Vector Assignment Approach For Inherent Strain Modeling Of Laser Powder Bed Fusion Manufacturing, Lucas M. Morand

All Dissertations

The expansion of the design space due to additive manufacturing (AM) has been a large motivator for the success of this family of processes. Despite the complexity of the physics in metal laser powder bed fusion AM causing significant stresses and strains in finished parts, the design advantages and subsequent performance improvements continue to drive the expansion of AM. Because the trial-and-error approach to AM part development is cost prohibitive, simulation of prints has become crucial. However, full thermo-mechanical simulation is susceptible to the same pitfall of time and computational cost in order to attain part-scale results. The development of …

Electrokinetic Particle Trapping Performance Of Conductive Nanofiber Mats In Microfluidic Wells., Jacob Hunter West

Electronic Theses and Dissertations

The frequency dependence of electrokinetic particle trapping using large-area (>mm²) conductive carbon nanofiber (CNF) mat electrodes is investigated. The fibers provide nanoscale geometric features for the generation of high electric field gradients, which is necessary for particle trapping via dielectrophoresis (DEP). A device was fabricated with an array of microfluidic wells for repeated experiments; each well included a CNF mat electrode opposing an aluminum electrode. Fluorescent microspheres (1 µm) were trapped at various electric field frequencies between 30 kHz – 1 MHz. Digital images of each well were analyzed to quantify particle trapping. DEP trapping by the …

Study Of Accidental Sliding-Mode Control, April Mary Miller

Theses and Dissertations

The objective of this paper is to examine the Quanser SRV-02 motor servo for the presence of an accidental sliding mode. The SRV-02 is used by undergraduate students to learn basic concepts in controls engineering and will display unexpected sliding mode behavior when its in the “out of box” configuration. To gain a strong background understanding in characteristics of sliding mode, a review of literature on sliding-mode control and sliding mode behavior is completed. Next, a theoretical analysis of the SRV-02 motor servo during the sliding mode is developed. An effort is made to find a Lyapunov function that proves …

Validating The Design Tensile Strength Of Grade 5 And Metric Class 8.8 Bolts, Paxton Charles Lifsey

Masters Theses

Bolted connections offer many benefits including ease of installation and maintenance and replaceable components, but must have sufficient strength in order to take advantage of these benefits. One of the major ways a bolted connection is loaded is under tension. In this loading condition, bolted connections can fail via tension in the threaded area, shear in the bolt threads, or shear in the nut threads. Standards such as FED-STD-H28/2B and ISO TR/16224 include equations for the stress area and strength of these limit states as well as for the required length of engagement such that tensile failure controls. These equations …

A Framework For Estimating Hybrid Manufacturing Costs, Nathan Joel Wilson

Masters Theses

Based on its potential to reduce lead times, hybrid manufacturing, which often includes both additive manufacturing and machining processes, is receiving more attention from manufacturers as they seek to increase their supply chain resilience and efficiency. A new solid-state additive manufacturing method, referred to as additive friction stir deposition (AFSD), has shown the potential to become an important process for hybrid manufacturing. To justify the selection of a hybrid manufacturing approach, the cost needs to be estimated for comparison to conventional approaches. This thesis proposes a suite of cost models that include AFSD, powder bed fusion (PBF), wire arc additive …

Deep Reinforcement Learning Of Variable Impedance Control For Object-Picking Tasks, Akshit Lunia

All Theses

The increasing deployment of robots in industries with varying tasks has accelerated the development of various control frameworks, enabling robots to replace humans in repetitive, exhaustive, and hazardous jobs. One critical aspect is the robots' interaction with their environment, particularly in unknown object-picking tasks, which involve intricate object weight estimations and calculations when lifting objects. In this study, a unique control framework is proposed to modulate the force exerted by a manipulator for lifting an unknown object, eliminating the need for feedback from a force/torque sensor. The framework utilizes a variable impedance controller to generate the required force, and an …