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Multi-Scale Analysis Of Multifunctional Composites And 3d Printed Polymers, Daniel Branden Perez

Open Access Dissertations

Methods of multi-scale analysis through combined physical testing and computational FEM were used to investigate structural battery composites and 3D printed polymers. Multifunctional composite structural batteries are materials capable of storing electrical energy while providing structural rigidity. Two battery cell configurations were considered: a carbon paper based cell with copper and aluminum foils, and a woven carbon fiber-based battery with nickel and iron deposition coatings. Flexural simulations were performed through simulated and physical three-point bend testing. Unidirectional carbon fiber layers in the place of the carbon paper can lead to up to a 233.73 GPa stiffness, significantly greater than the …

Estimation Of The Fatigue Life Of Additively Manufactured Metallic Components Using Modified Strain Life Parameters Based On Surface Roughness, Peter Grohs

Masters Theses

In this study, a method is developed to estimate the effects of surface roughness on the fatigue life of additively manufactured titanium Ti6Al4V, aluminum 7075–T6, and steel 4340 alloys through modified strain life parameters using finite element analysis (FEA). This method is highly beneficial to the fatigue analysis of as-built additively manufactured metal components, which possess rough surfaces that reduce fatigue life significantly but are challenging to analyze directly using finite element simulation because of complex geometries, i.e., modeling an exact surface profile is arduous.

An effective stress concentration factor, incorporating roughness data, is defined to quantify their effects on …

Exploring Convergence Of Snake Skin-Inspired Texture Designs And Additive Manufacturing For Mechanical Traction, Catherine Sue Tiner

Graduate Theses and Dissertations

This research focuses on the understanding, development, and additive manufacture of a 3D printed snake skin-inspired texture pattern. The design functionalities of snake skin were determined through the study of the snake species Python Regius otherwise known as the ball python. Each scale of a snake has hierarchical texture with hexagonal macro-patterns aligned on the ventral surface of the skin with overriding anisotropic micro textured patterns such as denticulations and fibrils. Using a laser-powder bed fusion (L-PBF) process, 420 stainless steel samples were 3D printed which closely resemble the above described directional texture of natural snake skin. This printed surface …

Exploration Of 3d Printingtechnologies For The Development Ofan Affordable Fluorescence Detector Forcapillary Separations, Kevin Do

Masters Theses

Capillary separation techniques offer fast separation for solutions of low detection volumeson the order of nL within seconds to minutes. However, detection efficiency is generallyreliant on high cost commercialized instrumentation. 3D printing is a relatively new andexciting field that has opened in the world of spectroscopic methods. The ability to quicklyfabricate devices have dramatically closed the gap between design and prototyping phasesof a project.In chapter 2, 3D printing technology will be used to design, develop, and optimize afluorescence detector that can be used as an alternative to commercial instruments. Thisdesign will follow exploration of integrated optics to further improve limits …

Material Characterization And Fracture Prediction Of Fdm Printed Parts, Sanchita Sheth

Mechanical and Aerospace Engineering Theses

In order to take advantage of the design freedom that Additive Manufacturing offers, most applications require reliable material characterization. This can ensure that a design performs within its environment and life requirements. This work discusses two models. One investigates the raster angle dependency of stiffness properties and the other numerically predicts fracture in Fused Deposition Modeling (FDM) printed polymer parts. Pre-processing of FDM geometry was done in Abaqus CAE (SIMULIA TM). FEA and post-processing was done in BSAM, which is a damage prediction software developed for composites. BSAM uses a regularized extended finite element approach of Discrete Damage Modeling. In …

Static Response Calibration Of 3d Printed Thin Walled Structures Using Fused Deposition Modelling, Akhilesh Ravindra Kulkarni

Mechanical and Aerospace Engineering Theses

3-D printing has enabled flexible, tool-less fabrication that yields numerous benefits. One benefit is unique and complex structural arrangements that increase design freedom to minimize weight. Such arrangements can be guided by advanced topology, shape, and sizing optimization tools using appropriate process constraints to ensure a printable design and can include highly integrated structural details such as stiffeners, flanges, frames, and other connections. 3D printing thin wall aircraft structures presents challenges for material and structural characterization. 3D printing enables integrated structural details, each detail is affected by the print process capability to fabricate the local geometry and deviations from designed …

Characterization Of Thermo-Mechanical Properties Of Copper Nano-Particles Infused Acrylonitrile Butadiene Styrene (Abs)- 3d Printed Specimens, Viswajit Talluru

Mechanical and Aerospace Engineering Theses

Now a days the use of metal nanoparticle infused polymer is becoming widespread, since the development of polymer with enhanced thermal properties are being used for the growth of electronic packaging industry. In this study, copper nanoparticles are mixed with the Acrylonitrile Butadiene Styrene (ABS) thermoplastic in varying mass proportions, to observe the changes in thermal and structural properties of ABS. As expected, the extruded wire with high nano-particle concentration exhibited much higher thermal conductivity than its raw ABS form. For the case of 2% copper nanoparticle infused ABS using one dimensional steady state heat flux method though extrude wire …

Application Of Halloysite Nanotubes In Bone Disease Remediation And Bone Regeneration, Yangyang Luo

Doctoral Dissertations

Customized patient therapy has been a major research focus in recent years. There are two research fields that have made a significant contribution to realizing individualized-based treatment: targeted drug delivery and three-dimensional (3D) printing technology. With benefit from the advances in nanotechnology and biomaterial science, various drug delivery systems have been established to provide precise control of therapeutic agents release in time and space. The emergence of three-dimensional (3D) printing technology enables the fabrication of complicated structures that effectively mimic native tissues and makes it possible to print patient-specific implants. My dissertation research used a clay nanoparticle, halloysite, to develop …

Three Dimensional Digital Alloying With Reactive Metal Inks, Chaitanya G. Mahajan

Theses

3D printing of multifunctional components using two or more materials is a rapidly growing area of research. Metallic alloy inks have been used with various 3D printing techniques to create functional components such as antennas, inductors, resistors, and biocompatible implants. Most of these printing techniques use premixed metallic alloy inks or nanoalloy particles with a fixed composition to fabricate the functional part. Since the properties of alloys vary with changes in the elemental composition, a printing process which could digitally dispense alloy inks having specific desired compositions would enable different functionalities and be highly desirable.

Using the binary copper-nickel system …

Improving The Isotropy Of Additively Manufactured Parts By Fused Deposition Modeling: From Polymeric Self-Assembly To Reactive Processing, Neiko Levenhagen

Doctoral Dissertations

This dissertation focuses on understanding how the interfacial segregation of low molecular weight polymeric species in a polymer blend impacts the interlayer adhesion and mechanical isotropy of objects prepared by fused deposition modeling (FDM), a widely used additive manufacturing technique. The molecular weight, architecture, and chemical identity of the low molecular weight polymer in the blend dramatically impacts the formation of a robust interlayer interface. Additional modification of the low molecular weight component presents opportunities for reactive processing. The impact of covalent bonds between interfacial layers on the interlayer adhesion and overall isotropy of an FDM printed object is examined.

Evaluation Of Lignin-Containing Photopolymers For Use In Additive Manufacturing, Jordan Sutton

Masters Theses

Generating high value products from lignin has been the goal of decades of research attempting to use the abundant byproduct of paper and biofuel production. Lignin’s complex aromatic structure means that it can potentially act as a feedstock for chemicals, fuels, and polymers. Bio-based polymers are a focus of discussion given the increasing concerns over polymer waste and renewability. For these reasons, efforts have been made to develop polymer products using lignin as an additive or a functionalized part of the polymer network. Photopolymerizable materials have been largely excluded from these works due to perceived difficulties understanding lignin’s photoactive structure. …

3d Printing Support-Less Engineered Lattice Structures Via Jetting Of Molten Aluminum Droplets, Dinesh Krishna Kumar Jayabal

Theses

Magnetohydrodynamic (MHD) metal jetting is a novel additive manufacturing method where parts can be manufactured by precisely depositing molten metal droplets. This thesis work explores the possibility of using such a method to print engineered lattice structures without the aid of any support material. It was determined through experiments that by carefully controlling the droplet jetting frequency, the droplet step-over distance, and the stand-off distance between the print head and the substrate, pillars with varying angles to the substrate could be printed. Also presented is the parameter study which maps droplets jetting frequency, and droplet step-over distance with the angle …

Hybrid Rocket Engines: Development Of Composite Fuels With Complex 3d Printed Ports, Alec William Yenawine

Open Access Theses

Hybrid rocket engines provide many advantages over current solid and liquid systems including: throttling capability, good specific impulse, and relatively low cost due to greater operational safety and simplicity. However, hybrid rockets are limited by low fuel regression rates and combustion efficiencies. In recent years, additive manufacturing (AM) has been implemented in the design, print, and testing of hybrid rocket fuels. AM has enabled design of fuel grains with complex port geometries which are not possible or difficult to achieve through conventional casting techniques. These geometries can be used to manipulate the oxidizer flow and fuel interactions to increase performance …

Handling History: An Exploration In The Use And Significance Of 3d Printing In Museum Exhibits, J Michelle Cordray

Electronic Theses and Dissertations

Museums have long been regarded as sacred spaces, housing a plethora of objects intended to be admires and contemplated upon, but too often they remain physically unreachable. This thesis project seeks to use the process of additive manufacturing, commonly known as 3D printing, to allow visitors to establish a more personal connection with museum items. The exhibit facilitated interaction between the Technology Sandbox and library visitors. This process included selecting items from the collection of the Art Museum of the University of Memphis, digitizing and printing items using the technology available in the Ned R. McWherter Library Technology Sandbox, creating …

Annealing Of Fused Filament Fabricated Nylon 6 With Elevated Isostatic Pressure, Anthony G. Tantillo

Theses

Fused filament fabrication (FFF) is the most common form of 3D-printing used today. It combines ease-of-use with broad material options that allow for a wide spectrum of applications. Parts made this way are still considered only prototypes due to their relatively weak strength as compared to traditional manufacturing methods. Two factors leading to a decrease in strength are the interior voids and poor bonding roads. A chamber was created to implement pressurized annealing cycles on nylon 6 co-polymer parts to decrease interior voids and increase road bonding. A designed experiment was used to determine main effect parameter estimates for five …

3d Printed Microfluidic Devices For Bioanalysis, Michael J. Beauchamp

Theses and Dissertations

This work presents the development of 3D printed microfluidic devices and their application to microchip analysis. Initial work was focused on the development of the printer resin as well as the development of the general rules for resolution that can be achieved with stereolithographic 3D printing. The next stage of this work involved the characterization of the printer with a variety of interior and exterior resolution features. I found that the minimum positive and negative feature sizes were about 20 μm in either case. Additionally, micropillar arrays were printed with pillar diameters as small as 16 μm. To demonstrate one …

Slm 125 Single Track And Density Cube Characterization For 316l Stainless Steel, Cullen Goss

Master's Theses

Selective Laser Melting is a rapidly developing additive manufacturing technique that can be used to create unique metal parts with tailormade properties not possible using traditional manufacturing. To understand the process from a most basic level, this study investigates system capabilities when melting single tracks of material. Individual tracks allow for a wide range of scan speeds and laser powers to be utilized and the melt pools analyzed. I discuss how existing studies and simulations can be used to narrow down the selection of potentially successful parameter combinations as well as the limitations of interpretation for single track information. Once …

Fabrication And Characterization Of Collagen-Polypyrrole Constructs Using Direct-Ink Write Additive Manufacturing, Rooshan Arshad

Electronic Thesis and Dissertation Repository

Current efforts in the tissue engineering field are being directed towards the creation of platforms which will facilitate in instructing cells towards biologically relevant outcomes such as stem cell differentiation and disease pathophysiology. Traditional fabrication methods serve as a limiting factor for the production of such platforms as they lack feature and geometric complexity. Additive Manufacturing (AM) offers advantage over said methods by affording designers creative freedom and great control over printed constructs. Such constructs can then be used to create appropriate models for study- ing a plethora of tissues and structures. An AM methodology for Direct-Ink Write (DIW) printing …

Defining Resizable Virtual Canvases Using 3d Printed Objects, Nolan M. Cooper

Honors Capstones

To work efficiently in an augmented reality (AR) environment, interactions with virtual objects must be closely integrated with familiar experiences in the real world. This project was designed to further current research into the use of 3D printed trackable objects for tracking to virtual objects in an AR environment. The positions of these real-world objects can be used to generate virtual surfaces, or canvases, and allow the user to direct their environment using easy to understand, tactile feedback. The project has been broken down into 3 basic components: 3D printing, object tracking, and virtual canvas generation. The complete GitHub repository …

Design, Mechanical Experiments And Modeling On A New Family Of 3d Printed Hybrid Chiral Mechanical Metamaterials With Negative Poisson’S Ratio, Yunyao Jiang

Doctoral Dissertations

Emerging in the last decade, mechanical metamaterials have many engineering advantages due to unusual mechanical properties. Auxetic (with negative Poisson’s ratio) mechanical metamaterials, as an important family of these materials, have broad engineering applications including the design of new materials with increased indentation resistance, shear resistance, energy absorption capability and variable permeability.

Chiral auxetic mechanical metamaterial is a sub-family of the auxetic material, which is with a geometry that is non-superposable on its mirror image. Compared to symmetric auxetic materials, such as re-entrant honeycombs or periodic porous materials, which have random handedness after instability, chiral materials have deterministic handedness and …

Designing A Human-Centric Rigid Body Armor For Female Police Officers: The Implications Of Fit On Performance And Gender Inclusivity, Sarah West

Graduate Theses and Dissertations

The lack of availability of female plates for police officers is an issue that has not been analyzed. Female anthropometry is uniformly different from male anthropometry. Currently available hard plates are flat. These plates may decrease coverage while increasing feelings of poor fit, discomfort, and poor mobility for both male and female officers. The plates designed for males offer the possibility of female officers experiencing feelings of gender exclusion. This research project explored the current perceptions of male and female police officers in Arkansas across the dimensions of fit, comfort, and mobility in the context of hard plate body armor. …

The Effect Of Porosity On Mechanical Properties Of Fused Deposition Manufactured Polymers And Composites, Eric Heartly Anderson

Master's Theses

Additive manufacturing has seen sustained growth in both consumer and industrial areas. fused deposition manufacturing (FDM), a specific additive manufacturing technology, has seen increased sales in consumer markets. In order to maintain growth, FDM will be increasingly used for load-bearing applications. However, the mechanical reliability of FDM polymers and composites is not well understood. This can be dangerous to property and safety. Presented in this paper are more than 16 distinct populations comprised of at least 23 unique tensile tests, a total of 506 tensile tests. Weibull statistics were used to quantify variance in physical properties of FDMed materials. It …

3d Printing A Microfluidic Chip Capable Of Droplet Emulsion Using Ninjaflex Filament, Robert Andrews

Mechanical Engineering Undergraduate Honors Theses

This paper details an investigation into methods and designs of 3D printing a microfluidic system capable of droplet emulsion using NinjaFlex filament. The specific field in which this paper’s experiment is rooted is dubbed “BioMEMS,” short for bio microelectromechanical systems. One prominent research area in BioMEMS is developing a “lab on a chip.” Essentially, the goal is to miniaturize common lab processes to the micro scale, rendering it possible to include these processes in a small chip. Reducing necessary sample sizes, shortening the reaction times of lab processes, and increasing mobility of lab processes can all be realized through microfluidic …

Experimental Study Of Condensation In Different 3d Printed Regenerators In A Thermoacoustic Cooler, Aibek Bekkulov

Theses and Dissertations

Thermoacoustics (TA) deals with the conversion of heat into sound and vice versa. Device that converts heat into acoustic work is called TA heat engine, while the device that transfers energy from a low temperature reservoir to a high temperature one by utilizing acoustic work is called TA cooler. A simple construction of TA cooler includes an acoustic speaker, a resonator tube and a regenerator stack in which the temperature gradient is being imposed. Such a TA cooler has several advantages over traditional compression/expansion cooling machine such as its simplicity of the construction, high reliability and lack of toxic refrigerants. …

Developing Portable Tools Based On Magnetophoresis For Accessible Clinical Diagnostics, Stephanie Knowlton

Doctoral Dissertations

Modern technological advancements allow us to study human cells with an extraordinary level of detail and accuracy. However, the impact of these technologies on public health remains limited by their complexity, cost, and inaccessibility. Hence, there is a need for user-friendly, inexpensive tools that can be used at the point of care, in limited-resource settings, and at home. Therefore, we aim to develop a platform technology that can perform a variety of medical diagnostics to rapidly provide important information in order to best inform medical decisions. Magnetophoresis is a phenomenon that enables precise manipulation of particles that do not necessarily …

Process Planning For Concurrent Multi-Nozzle 3d Printing, Paritosh Santosh Mhatre

Theses

Additive manufacturing (AM) processes possess excellent capabilities for manufacturing complex designs as single uniform parts with optimum material utilization. However, the processes are still not widely used in industry to make large parts. The main reason for this slow adoption is the low material deposition rate during printing. Increasing the material deposition rate by increasing the layer thickness or utilizing larger diameter nozzles results in deterioration of the surface quality of the part. This is known as the “staircase effect”; thus there is a trade-off between the print time and the surface finish of a part. A majority of the …

Non-Contact Height Estimation For Material Extrusion Additive Systems Via Monocular Imagery, Andrew C. Gorospe

Theses and Dissertations

Additive manufacturing is a dynamic technology with a compelling potential to advance the manufacturing industry. Despite its capacity to produce intricate designs in an efficient manner, industry still has not widely adopted additive manufacturing since its commercialization as a result of its many challenges related to quality control. The Air Force Research Laboratory (AFRL), Materials and Manufacturing Directorate, Functional Materials Division, Soft Matter Materials Branch (RXAS) requires a practical and reliable method for maintaining quality control for the production of printed flexible electronics. Height estimation is a crucial component for maintaining quality control in Material Extrusion Additive Manufacturing (MEAM), as …

Design And Process Of 3d-Printed Parts Using Composite Theory, Jordan Garcia

Theses and Dissertations--Mechanical Engineering

3D printing is a revolutionary manufacturing method that allows the productions of engineering parts almost directly from modeling software on a computer. With 3D printing technology, future manufacturing could become vastly efficient. However, it is observed that the procedures used in 3D printing differ substantially among the printers and from those used in conventional manufacturing. In this thesis, the mechanical properties of engineering products fabricated by 3D printing were comprehensively evaluated and then compared with those made by conventional manufacturing. Three open-source 3D printers, i.e., the Flash Forge Dreamer, the Tevo Tornado, and the Prusa, were used to fabricate the …

Physical And Optical Properties Of Provisional Crown And Bridge Materials Fabricated Using Cad/Cam Milling Or 3d Printing Technology, Niranjan Joshi

Student Theses, Dissertations and Capstones

Objective: This study compared the physical and optical properties of provisional crown and bridge materials fabricated using CAD/CAM or 3D printing technology. Aim: To compare the biaxial flexural strength, microhardness, translucency parameter and gloss of provisional resin discs fabricated by milling PMMA blocks, versus two different resins printed using 3D printers. Hypothesis: There is no difference in the flexural strength, hardness, translucency and gloss of provisional resins fabricated by different digital technologies. Materials and methods: 90-disc shaped specimens for provisional resins were fabricated using a common digital file. These samples were equally distributed in three groups of 30 each. Group …

Properties And Applications Of Tetraalkylphosphonium Alkylsulfate Ionic Liquids And 3d Printed Polymerized Ionic Liquids, Mustafa Mohammed Alhussain

Murray State Theses and Dissertations

Ionic liquids (ILs) are defined as pure salts with a melting temperature below 100 °C with a subset called room-temperature ILs (RTILs) with melting temperatures at or below room temperature. The sizes of the cation and anion play a critical role in determining the properties, with smaller ions forming stronger ionic forces and packing better, raising viscosity and lowering conductivity of the IL. At the same time, intermolecular forces such as van der Waals and hydrogen bonding can play a role in IL properties as well. Our research described herein is focused on three tetraalkylphosphonium-based cations coupled with three alkylsulfate …