Mechanical Engineering Commons^™

Effect Of Autoclave Process Parameters On Mechanical Behaviors Of Carbon Fiber Reinforced Polymer Composites Fabricated Via Additive Manufacturing, Quang Hao Nguyen

Honors Undergraduate Theses

Additively manufactured carbon fiber reinforced polymers (CFRP) are vastly studied for their remarkable mechanical properties compared to most other 3D printed materials. Different methods were employed to further increase mechanical performance of CFRP 3D printed parts. The objective of the study is to investigate the effect of autoclave postprocessing on the interlaminar shear behavior between 3D printed CFRP layers. 3D printed CFRP samples were processed with nine combinations of temperature and vacuum in an autoclave. Short beam shear (SBS) tests were performed to characterize the interlaminar shear strength (ILSS) of the samples after autoclave processing. Digital image correlation (DIC) was …

Variational Autoencoder And Sensor Fusion For Robust Myoelectric Controls, Keith A. Currier

Honors Undergraduate Theses

Myoelectric control schemes aim to utilize the surface electromyography (EMG) signals which are the electric potentials directly measured from skeletal muscles to control wearable robots such as exoskeletons and prostheses. The main challenge of myoelectric controls is to increase and preserve the signal quality by minimizing the effect of confounding factors such as muscle fatigue or electrode shift. Current research in myoelectric control schemes are developed to work in ideal laboratory conditions, but there is a persistent need to have these control schemes be more robust and work in real-world environments. Following the manifold hypothesis, complexity in the world can …

Effect Of Particle Size On Mechanics Of Particle Reinforced Composites Using Photoluminescence Piezospectroscopy, Khanh Vo

Electronic Theses and Dissertations, 2020-2023

Nanoparticle reinforced composites are greatly desired by the aerospace community for a multitude of applications for their tailorable quasi-isotropic mechanical properties such as the high strength-to-weight ratio. With increasing demand of structural nanoparticulate composites, the optimization of their structural integrity and performance can be improved with a better understanding of the load transfer mechanics. Extensive nanoparticulate composites research has focused on the roles of particle shape, size, and volume fraction on the mechanical properties. Nanocomposites are often experimentally characterized through the determination of the bulk composite material properties. Load transfer research with a micro-mechanics perspective, distinguishing particle and matrix behavior, …

Machine Learning Applications In Advanced Additive Manufacturing: Process Modeling, Microstructure Analysis, And Defect Detection, Peter Warren

Electronic Theses and Dissertations, 2020-2023

Non-destructive evaluation (NDE) techniques are critical for assessing the integrity, health, and mechanical properties of materials manufactured from various methods. High fidelity NDE techniques are essential for quality control but often lead to massive data generation. Such a vast data load cannot be manually processed, this leads to a severe bottleneck for process engineers. Machine learning (ML) offers a solution to this problem by providing powerful and adaptable algorithms capable of learning patterns, identifying features, and finding hidden relationships in large sets of data. Various ML models are used in this work to improve predictions, improve measurements, detect anomalies, classify …

Investigation Of Fiber Orientation And Mechanical Properties Of Pyrolysis Recycled Carbon-Fiber Reinforced Thermoset Composite, Reva N. Simmons, Harry Lee, Garam Kim

Discovery Undergraduate Interdisciplinary Research Internship

With increasing demand of carbon fiber reinforced fiber thermoset composites, establishing a sustainable cycle for these materials becomes crucial. Pyrolysis is a process of reclaiming carbon fiber from thermoset composites by thermally degrading the polymer at high temperatures allowing the fibers to be extracted. Carbon fiber reclaimed through current pyrolysis processes for thermoset composites typically loses its original shape and orientation, making it difficult to reorganize the fibers. This study investigated the feasibility of maintaining the fiber orientations for continuous fiber reinforced thermoset composite during pyrolysis by stitching the carbon fiber layup to a conformable copper mesh during the manufacturing …

3d Simulation Of A Yogurt Filling Machine Using Grafcet Studio And Factory Io: Realization Of Industry 4.0, Bashir Salah, Waqas Saleem, Razaullah Khan, Ahmed Tawhid Ahmed Soliman

Articles

Manufacturing systems, enterprises and academic institutions worldwide are implementing industry 4.0 (IR4.0). By integrating the services and equipment, IR4.0 develops autonomous systems that manage industrial operations and exchange real-time data in real time. This study includes a simulation of an existing production system using the GRAFCET Studio software.

Advances In Precision Microfabrication Through Digital Light Processing: System Development, Material And Applications, Xinhui Wang, Jinghang Liu, Yang Zhang, Per Magnus Kristiansen, Aminul Islam, Michael Gilchrist, Nan Zhang

Articles

Digital Light Processing (DLP) is an advanced additive manufacturing technology which has garnered substantial recognition and has been extensively applications in various fields. This review focuses on the precision microfabrication process of DLP, providing an overview of the DLP 3D printing system, including the digital light engine, project lenses, motorised stage and resin vat for micro-structure fabrication. Additionally, this review paper comprehensively analyses commercially available DLP printers, covering resolution, cost and a detailed discussion on the importance of photopolymer resins, emphasising the monomer, photo-initiator, photoabsorber, etc. Based on the photopolymerisation theory, the DLP high-precision printing process is analysed, which is …

Board 341: Mobile Learning In Stem: A Case Study In An Undergraduate Engineering Course, Krishna Pakala, Maeve Bakic, Diana Bairaktarova, Devshikha Bose

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Student-centered educational system is needed for better educational outcomes. Technology enabled pedagogy has helped immensely during the pandemic times when rapid transition to remote learning was essential. This poster reports findings on year one of a two-year research study to utilize mobile technologies and a technology-enhanced curriculum to improve student engagement and learning in STEM undergraduate courses. This poster describes a quasi-experimental mixed methods study on implementing mobile devices (iPad and Pencil) and a technology-enhanced curriculum in an undergraduate thermal-fluids engineering course, a foundational engineering class.

The technology-enabled curriculum was fully integrated in the thermal-fluids course to deliver content and …

3d-Printed Hydrogels Dressings With Bioactive Borate Glass For Continuous Hydration And Treatment Of Second-Degree Burns, Fateme Fayyazbakhsh, Michael J. Khayat, Candy Sadler, Delbert Day, Yue-Wern Huang, Ming-Chuan Leu

Biological Sciences Faculty Research & Creative Works

Recent advances in additive manufacturing have led to the development of innovative solutions for tissue regeneration. Hydrogel materials have gained significant attention for burn wound treatment in clinical practice among various advanced dressings due to their soothing and moisturizing activity. However, prolonged healing, pain, and traumatic removal due to the lack of long-term wound hydration are some of the challenges in the treatment of second-degree burn wounds. In this study, 3D-printed dressings were fabricated using gelatin, alginate, and bioactive borate glass (BBG) using an extrusion-based bioprinter. After ionic crosslinking, the 3D-printed dressings were characterized for mechanical properties, degradation rate, hydration …

Modeling Of Expansion Of Laser-Produced Aluminum Plasma Plume In Ambient Air, Edmund Tsiri Semaha

Graduate Research Posters

When a laser pulse is focused on an aluminum target, it interacts with the material’s surface and a plasma plume is developed. Hydrodynamic expansion of generated plasma plume consisting of interacting target and ambient gaseous species remain one of very significant subjects of plasma plume chemistry, yet to be fully understood. The revealing of fundamental physics processes which occur within these plasma plumes is not only of purely scientific advancement, but it is also of industrial interest. Our research focuses on the development of Computational Fluid Dynamics (CFD) model that is used to investigate the chemistry of expanding plasma generated …

Classifying Multi-Generational Products For The Circular Economy, Buddhika M. Hapuwatte, Fazleena Badurdeen, I. S. Jawahir

Institute for Sustainable Manufacturing Faculty Publications

Manufacturers are increasingly interested in the circular economy (CE) and potential of circular productions. To fully utilize CE, better guidance at the design stage is needed to establish closed-loop flows and prioritize higher value retaining end-of-use (EoU) practices such as reuse and remanufacture (i.e., parts harvesting). Intergenerational commonality (IC) is a method to increase EoU parts harvesting. However, closed-loop parts harvesting potential depends on the compatible timing between design generations’ production and EoU returns curves. Therefore, in this paper, we explore an approach to make an initial assessment on where IC as a closed-loop CE strategy can produce most benefit, …

Design Of Force Indicator For Ballistic Armor Trauma Pad, William Keenan, Anthony Cinalli, Patrick Kennedy

Williams Honors College, Honors Research Projects

The purpose of the Force Indicator for Ballistic Armor Vests is to obtain an approximate value for the impact a bullet delivers through a trauma pad after the Kevlar layer stops the initial bullet. This approximation will be applied in the field to assist in medical treatment of gunshot wounds. The indicator is made from a pressure-sensitive film located behind the Kevlar layer and trauma pad, and it can be easily removed in the field for examination. The impact vest and force indicator are self-contained for ease of implementation. The device will be tested with 9mm, .22 Long Rifle, and …

An Experimental Study On The Mechanical Properties And Chemical Composition Of Lcd 3d Printed Specimens, Sebastian Gomez

College of Graduate Studies: Theses & Dissertations

Additive manufacturing technologies have been enhanced throughout the years yet have surprised the manufacturing industry due to their high-end surface finish and dimensional accuracy. Different experiments have been done to identify a specific phenomenon known in the vat-polymerization field. Distortion and dimensional inaccuracy tend to affect the overall properties of the process, either physical or chemical. This approach allows the understanding of how the physical properties have been affected and how to study the chemical properties to avoid this type of phenomenon. The chemical reaction between polymer and UV light has been studied and experimented with to the point that …

Design And Fabrication Of A Force-Displacement Control Mechanism For Bone-Surgical Tool Testing, Kenneth Nwagu

College of Graduate Studies: Theses & Dissertations

This project focuses on the design and fabrication of an experimental setup for orthopedic-tool testing, tailored for a surgical instrumentation company. The multifaceted project encompasses a literature review, conceptual design, prototyping, and rigorous testing, resulting in a versatile control system capable of assessing various orthopedic tools, including bone drills, saws, burrs, and power handpieces.

Orthopedic surgical procedures (which include cutting and/or drilling into bone) often need to be performed on bones for faster recovery. The drilling and cutting process can cause an increase in temperature at the cutting site which can cause bone necrosis. The tools also need to be …

Material Extrusion-Based Additive Manufacturing: G-Code And Firmware Attacks And Defense Frameworks, Haris Rais

Theses and Dissertations

Additive Manufacturing (AM) refers to a group of manufacturing processes that create physical objects by sequentially depositing thin layers. AM enables highly customized production with minimal material wastage, rapid and inexpensive prototyping, and the production of complex assemblies as single parts in smaller production facilities. These features make AM an essential component of Industry 4.0 or Smart Manufacturing. It is now used to print functional components for aircraft, rocket engines, automobiles, medical implants, and more. However, the increased popularity of AM also raises concerns about cybersecurity. Researchers have demonstrated strength degradation attacks on printed objects by injecting cavities in the …

Investigation Of Endothelial Mechanics On Primary Cell Functions: Endothelium Permeability And Wound Healing, Sean Beverung

Electronic Theses and Dissertations, 2020-2023

The endothelium composes the inner lining of blood vessels, the heart, and lymphatic vessels. Within the cardiovascular system, it is an extremely important structure, aiding in the regulation of blood pressure with the vascular tone, recruiting immune response, regulating the transfer of material in and out of the bloodstream, and the creation of new blood vessels through angiogenesis. The endothelium is composed entirely of endothelial cells. These cells lay in a flat squamous formation and are in direct contact with blood and aid in the regulation and transfer of material in and out of the bloodstream via active and passive …

Investigation Of Manufacturing Techniques For Magnetorheological Elastomers To Expand Feasibility In A Diverse Array Of Applications, Austin S. Robbins

College of Graduate Studies: Theses & Dissertations

Magnetorheological elastomers, or MREs, are smart composite materials with controllable physical and mechanical properties when introduced to an external stimulus of a magnetic field. The controllability of these properties is highly tunable by the selection of the elastomeric matrix, concentration of magnetically permeable particles, introduction of additives, and the alignment of the constituents during the curing process. The fabrication of MREs typically calls for a mold that is filled with an MRE mixture to create the final desired geometry after curing. These molds are frequently placed under a magnetic field which orients the micron sized magnetic particles along the magnetic …

Synthesis And Processing Of Pcl And Irdye Nanoparticles For Application In Drug Release Mechanism, Michael Adeniyi

College of Graduate Studies: Theses & Dissertations

The objective of this study is to produce core-shell nanoparticles utilizing PCL and IRDye and investigate the nanoparticle release mechanism. Biodegradable polymer, Polycaprolactone (PCL), was electrosprayed separately with two types of IRDye, NHS and Dextran Texas red. The solution of PCL was formed by mixing PCL in a solution of 9.47ml Acetic Acid, 9.47ml Formic Acid, and 1.05ml Trifluoroethanol, following a ratio of 9:9:1. The two solutions of IRDye were prepared by mixing 2mg of the IRdye with 20ml of DMF at a rate of 0.1mg/ml.

The NHS IRDye was electrosprayed coaxially with PCL and the Dextran Texas red dye …

Peridynamic Simulation Of Elastic Wave Propagation By Applying The Boundary Conditions With The Surface Node Method, Francesco Scabbia, Mirco Zaccariotto, Ugo Galvanetto, Florin Bobaru

Department of Mechanical and Materials Engineering: Faculty Publications

Peridynamics is a novel nonlocal theory able to deal with discontinuities, such as crack initiation and propagation. Near the boundaries, due to the incomplete nonlocal region, the peridynamic surface effect is present, and its reduction relies on using a very small horizon, which ends up being expensive computationally. Furthermore, the imposition of nonlocal boundary conditions in a local way is often required. The surface node method has been proposed to solve both the aforementioned issues, providing enhanced accuracy near the boundaries of the body. This method has been verified in the cases of quasi-static elastic problems and diffusion problems evolving …

A New Course In Defense Manufacturing – An Introduction To Shipbuilding, Alley C. Butler

Manufacturing & Industrial Engineering Faculty Publications

This paper discusses the development and deployment of a new course in DMEI (Defense Manufacturing Engineering Innovation) titled, “Introduction to Shipbuilding.” This course has been taught using Zoom since 2021 at both the University of Texas Rio Grande Valley, a Hispanic Serving Institution, and Virginia State University, a Historically Black University. After a brief literature review, an outline of the course is presented with topics including the maritime market for shipbuilding, economics of shipbuilding, the classification agencies, metallurgy and welding processes, ship structure and assembly, shipyard layout, accuracy control, and shipbuilding planning and scheduling. Difficulties in obtaining an appropriate textbook …

Topologically Optimized Electrodes For Electroosmotic Actuation, Jianwen Sun, Jianyu Zhang, Ce Guan, Teng Zhou, Shizhi Qian, Yongbo Deng

Mechanical & Aerospace Engineering Faculty Publications

Electroosmosis is one of the most used actuation mechanisms for the microfluidics in the current active lab-on-chip devices. It is generated on the induced charged microchannel walls in contact with an electrolyte solution. Electrode distribution plays the key role on providing the external electric field for electroosmosis, and determines the performance of electroosmotic microfluidics. Therefore, this paper proposes a topology optimization approach for the electrodes of electroosmotic microfluidics, where the electrode layout on the microchannel wall can be determined to achieve designer desired microfluidic performance. This topology optimization is carried out by implementing the interpolation of electric insulation and electric …

Effect Of Platelet Length And Stochastic Morphology On Flexural Behavior Of Prepreg Platelet Molded Composites, Siavash Sattar, Benjamin Beltran Laredo, Sergii G. Kravchenko, Oleksandr G. Kravchenko

Mechanical & Aerospace Engineering Faculty Publications

Prepreg platelet molding compound (PPMC) can be used to create structural grade material with a heterogeneous mesoscale morphology. The present work considered various platelet lengths of the prepreg system IM7/8552 to study the effect of platelet length on the flexural behavior of PPMC composite. A progressive failure finite-element analysis was used to understand competing failure modes in PPMC with the different platelet length. The interlaminar and in-plane damage mechanisms were employed to describe complex failure modes within the mesostructure of PPMCs. Experimental results of the flexural tests of the PPMC with different platelet length sizes were used to validate the …

Performance Evaluation Of Composite Sandwich Structures With Additively Manufactured Aluminum Honeycomb Cores With Increased Bonding Surface Area, M. Rangapuram, S. K. Dasari, Joseph William Newkirk, K. Chandrashekhara, H. Misak, P. R. Toivonen, D. Klenosky, T. Unruh, J. Sam

Materials Science and Engineering Faculty Research & Creative Works

Modern aerostructures, including wings and fuselages, increasingly feature sandwich structures due to their high-energy absorption, low weight, and high flexural stiffness. The face sheet of these sandwich structures are typically thin composite laminates with interior honeycombs made of Nomex or aluminum. Standard cores are structurally efficient, but their design cannot be varied throughout the structure. With additive manufacturing (AM) technology, these core geometries can be altered to meet the design requirements that are not met in standard honeycomb cores. This study used a modified aluminum honeycomb core, with increased surface area on the top and bottom, as the core material …

การศึกษาการตรวจหาเชื้อวัณโรคจากภาพย้อมสีทนกรดโดยใช้การเรียนรู้เชิงลึกด้วยเทคนิคการจำแนกและการตรวจจับวัตถุ, ธีริศรา มิคาระเศรษฐ์

Chulalongkorn University Theses and Dissertations (Chula ETD)

การศึกษานี้เป็นการวิเคราะห์ Deep Learning สำหรับตรวจหาเชื้อวัณโรคด้วยวิธีการ Modified Classification และ Object Detection โดยใช้ Pre-Trained Model คือ Enhanced ResNet50 และ AlexNet ในการวิเคราะห์ ซึ่งวิธี Modified Classification มีการนำ Image Processing มาประยุกต์ใช้กับการทดลอง เมื่อ Training ข้อมูล พบว่า ResNet50 เป็น Model ที่มีประสิทธิภาพสูงสุดได้ค่า Accuracy เท่ากับ 92.71% และ Precision เท่ากับ 92.7% เมื่อจัดกลุ่มใหม่สำหรับการวิเคราะห์ แบบ Suspected Positive Low Confidence และ Suspected Positive High Confidence ผลการทดลองพบว่า ResNet50 ยังคงมีประสิทธิภาพที่ดีที่สุด มีค่า Accuracy เท่ากับ 98.06% ค่า Precision เท่ากับ 98.59% ส่วน Suspected Positive High Confidence มีค่า Accuracy เท่ากับ 94.38% และค่า Precision เท่ากับ 91.41% และในการวิเคราะห์ Deep Learning วิธี Object Detection ได้ค่า Precision เท่ากับ 82.81% และ Mean AP เท่ากับ 36.79% จากการเปรียบเทียบการวิเคราะห์ทั้ง 2 Models พบว่า วิธีวิเคาระห์แบบ Modified Classification ได้ผลลัพทธ์ดีกว่า จึงนำไปตรวจร่วมกับวิธีการตรวจของแพทย์ (Doctor …

Utilisation Des Ponts Élévateurs De Véhicules Hors Terre À Deux Colonnes : Identification De Déterminants Techniques De Stabilité Et Des Déterminants Du Travail Des Techniciens Automobiles, Damien Burlet-Vienney, Sylvie Beaugrand, Bertrand Galy, Maud Gonella, François Gauthier, Élise Ledoux, Isabelle Berger, Isvieysys Armas Marrero, Kariane Cusson Bertrand

Rapports de recherche scientifique

Cette recherche porte spécifiquement sur l’utilisation des ponts élévateurs de véhicules (PEV) hors terre à deux colonnes (HT2C). Les PEV HT2C sont utilisés par les techniciens automobiles lors de l’entretien et de la réparation des véhicules et les amènent à travailler sous ou à proximité d’une charge surélevée de plusieurs tonnes. La mort d’un jeune technicien en 2014 est à l’origine d’une concertation du secteur de la réparation automobile et de ces travaux de recherche. La chute d’un véhicule d’un PEV HT2C est le risque ciblé par cette étude.

De nombreux facteurs sont susceptibles de contribuer à la chute d’un …

Thermal Performance And Fluid Flow Studies Of Twisted Tape Inserts Using Scaled Surrogate Fluids For Molten Salt Energy Applications, Arturo Cabral

Theses and Dissertations

Global energy consumption is expected to increase with population growth and innovative clean sources of energy are sought out that can help meet the needs of a continuously power-hungry world. Some of these innovative sources of energy use molten salts as their operating and cooling fluid, such as fission reactors, fusion reactors, and solar power with energy storage. Molten salts are considered due to their efficient heat transfer properties, thermal energy storage capabilities, and high operating temperatures. To expedite their deployment, a further understanding of the heat transfer systems is required to accurately design and develop the heat transfer components …

Advanced Modeling And Innovative Transcranial Magnetic Stimulation Coil Designs For The Treatment Of Neurological Disorders, Mohannad Tashli

Theses and Dissertations

Transcranial magnetic stimulation (TMS) is a safe, effective and non-invasive treatment for several mental and psychiatric disorders. TMS is an FDA approved treatment and is commonly applied to patients who do not respond to medications for the treatment of clinical depression, smoking cessation, obsessive-compulsive disorder and migraine. Recently, there has been an increase in the development of electromagnetic neuromodulation techniques targeted at enhancing the effectiveness of TMS devices for the treatment of mental diseases. In TMS stimulation, focality is an important factor which determines the specificity of the pulses induced in different brain tissues. The electromagnetic pulses must be confined …

Full Body Harness Design Modifications And Evaluation: A Senior Design Project, Martin Mead, Jordan Von Seggern

The Journal of Undergraduate Research

Full-body harness (FBH) is critical for the safe operation of industrial and recreational activities, from installing and maintaining infrastructure such as wind turbines to ziplining and mountaintop adventures. However, harness design remains in the proprietary information of companies with limited technical information available for improvements or readjustments to specialized applications. As the outcome of the Capstone project, the paper focuses on multiple technical aspects and the engineering processes for designing FBH for ziplining recreational users, from selecting and testing materials for operation in cold weather to improvements in design and manufacturing for user comfort. The project is guided by technical …

Quantifying The Effects Of Hvac Operation To Mitigate Aerosol Concentration In A Classroom Using Cfd, Scott Deprez

Electronic Theses and Dissertations

Heating, ventilation, and air conditioning (HVAC) is a complex mechanical system for the transition of air between outdoor and indoor areas. These systems are directly responsible for temperature, humidity, and air flow into any given space, thereby providing a level of comfort to those who live indoors. These systems account for 52 percent of U.S. energy consumption. When designing HVAC systems, indoor air quality (IAQ) is the main focus for achieving safe and clean air, such as in the case of airborne diseases. HVAC systems are responsible for the flow of air in indoor spaces and thereby expand the transmissible …

Nonprehensile Manipulation Of A Stick Using Impulsive Forces, Aakash Khandelwal, Nilay Kant, Ranjan Mukherjee

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The problem of nonprehensile manipulation of a stick in three-dimensional space using intermittent impulsive forces is considered. The objective is to juggle the stick between a sequence of configurations that are rotationally symmetric about the vertical axis. The dynamics of the stick is described by five generalized coordinates and three control inputs. Between two consecutive configurations where impulsive inputs are applied, the dynamics is conveniently represented by a Poincaré map in the reference frame of the juggler. Stabilization of the orbit associated with a desired juggling motion is accomplished by stabilizing a fixed point on the Poincaré map. The Impulse …