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Articles 1 - 12 of 12
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Design And Customization Of 3d Printers For Advanced Materials Printing, Alan Omar Loera Martinez
Design And Customization Of 3d Printers For Advanced Materials Printing, Alan Omar Loera Martinez
Open Access Theses & Dissertations
This research is divided into two sections. The first section discusses modificationsperformed to two commercial printers. The first printer was modified from a thermoplastic polymer printer to a pneumatic printer by taking away its heating elements and print head. Circuits were directed to pneumatic dispensing system as well in order to automate the process. The second printer had mechanical modifications performed to be a multi-material gradient printer by controlling two stepper motors through an electronics board. Through code, a mixing ratio changed the motors' rotations to provide the desired gradient of two different materials. The second section of the present …
Ultrasonic Non-Destructive Evaluation Of Additively Manufactured Polymer-Ceramic Composites, Christian Alexander Ruiz
Ultrasonic Non-Destructive Evaluation Of Additively Manufactured Polymer-Ceramic Composites, Christian Alexander Ruiz
Open Access Theses & Dissertations
Digital light processing (DLP) is an attractive additive manufacturing technique due to its ability to create ceramic parts with complex geometries. DLP uses ultraviolet light to polymerize a slurry comprised of ceramic powder and photosensitive resin in layers to create solid parts. Printing parameters such as light intensity and exposure time are critical when producing these parts. Improper parameters can lead to over or under-curing, adversely impacting print quality and strength. Samples were printed at varying layer exposure times and then tested using ultrasonics to determine the degree of conversion. Additionally, ultrasonics were used as a non-destructive technique to obtain …
Additive Manufacturing Of Composites For Sensing And Harsh Environments Application, Md Sahid Hassan
Additive Manufacturing Of Composites For Sensing And Harsh Environments Application, Md Sahid Hassan
Open Access Theses & Dissertations
Composite materials are made by combining two or more materials, such as fibers and resins to create a material system that has improved mechanical and physical properties compared to its individual components. The use of 3D printing technology in composite manufacturing allows for the creation of complex and custom shapes with precise control over the placement of the materials. This makes it possible to create composite parts with enhanced performance characteristics and reduced weight. The work presented in this dissertation lies in the design and development of highly flexible impact propagation sensor through material extrusion 3D printing technique. By using …
An Optimization Procedure To Design Nozzle Contours For Hypersonic Wind Tunnels, Omar Antonio Dominguez
An Optimization Procedure To Design Nozzle Contours For Hypersonic Wind Tunnels, Omar Antonio Dominguez
Open Access Theses & Dissertations
Supersonic wind tunnels allow scientists and researchers to evaluate and analyze the behaviors of objects under real-life conditions when subjected to supersonic speeds. One of the main complexities when building a wind tunnel is the design of the convergent-divergent nozzle that is used to produce high-speed and high-quality flows. To achieve supersonic speeds, this nozzle adopts a specialized approach that incorporates the complexities of flow compressibility. The compressible effect is accurately evaluated using isentropic relations, allowing for precise determination of stagnation pressure and temperature, and static pressure and temperature relevant to the desired Mach number. Isentropic equations used to define …
Enhancing Damage Tolerance Of The Constituents Of Sandwich Composites, Zackery Nieto
Enhancing Damage Tolerance Of The Constituents Of Sandwich Composites, Zackery Nieto
Open Access Theses & Dissertations
Composite structures have become a lucrative material choice for researchers throughout various sectors such as green energy, arctic travel, and aerospace application due to their light weight, high-bending to stiffness ratio, and job tailorable applications through material selection. With the increasing demand for new and better composite technologies growing each year it is imperative to investigate new materials and analytical options to help the composite field as a whole grow. In this report various materials and statistical applications have been studied regarding the constituent materials in sandwich composites. For core materials an additive manufactured photoreactive resin has been characterized for …
Double Cantilever Beam Mode-I Testing Validation In Large-Scale Additive Manufacturing Carbon Composite, Luis Alfonso Camacho
Double Cantilever Beam Mode-I Testing Validation In Large-Scale Additive Manufacturing Carbon Composite, Luis Alfonso Camacho
Open Access Theses & Dissertations
Testing for mechanical properties for additive manufacturing has been based on already existing standards for traditional manufacturing methods. For composites in large scale additive manufacturing there is a research gap in bond strength and fracture toughness for a single layer interface. By using Double cantilever beam Mode I, this thesis manuscript validates testing parameters and protocols to describe the intricacies of ABS matrix 20 wt.% carbon filled composite, specifically on the layer-to-layer interface. Studies suggest that fracture toughness is sensitive to process parameters, like deflection speed and sharpened crack tip at the layer interface of BAAM 3D printed part and …
The Effects Of Process Parameters On The Cyclical Life Of Ti-6al-4v Manufactured Via Laser Powder Bed Fusion, Brandon Ramirez
The Effects Of Process Parameters On The Cyclical Life Of Ti-6al-4v Manufactured Via Laser Powder Bed Fusion, Brandon Ramirez
Open Access Theses & Dissertations
Additive manufacturing via Laser Powder Bed Fusion (LPBF) has already proven revolutionary technology. Due to its favorable strength-to-weight ratio, ti-6Al-4V, a popular titanium alloy, has already been implemented in the aerospace industry for various components. However, the quality validation in additively manufactured parts has always been an issue of concern, specifically under cyclic loading. Ti-6Al-4V samples were printed using LPBF with various process parameters to investigate these conditions further. The build was stress-relieved; however, the samples underwent no other post-processes maintaining their as-built surface. The process parameters were separated into five categories, including various laser powers and printing speeds, allowing …
Computational Analysis Of Water Braking Phenomena For High-Speed Sled And Its Machine Learning Framework, Jose A. Terrazas
Computational Analysis Of Water Braking Phenomena For High-Speed Sled And Its Machine Learning Framework, Jose A. Terrazas
Open Access Theses & Dissertations
Specializing in high-speed testing, Holloman High-Speed Test Track (HHSTT) uses a process called "water braking" as a method to bring vehicles at the test track to a stop. This method takes advantage of the higher density of water, compared to air, to increase braking capability through momentum exchange. By studying water braking using Computational Fluid Dynamics (CFD), forces acting on track vehicles can be approximated and prepared for prior to the actual test. In this study, focus will be made on the brake component of the track sled that is responsible for interacting with the water for braking. By discretizing …
A Method For Measuring The Spectral Emissivity Of Metal Powders At Different Temperatures And Applications In Laser Powder Bed Fusion, Emmanuel Levario
A Method For Measuring The Spectral Emissivity Of Metal Powders At Different Temperatures And Applications In Laser Powder Bed Fusion, Emmanuel Levario
Open Access Theses & Dissertations
Radiation thermometry monitoring methods used in powder bed fusion additive manufacturing (PBF-AM) are becoming increasingly more popular for quality assurance and repeatability. The dynamic nature of the PBF process and a lack of accuracy of metrics being captured for temperature monitoring lend great difficulty in the successful implementation of in-situ monitoring. There is currently no data on the emissivity, a metric used in non-contact temperature measurements, for metal powders used in AM. This work describes a method for measuring the spectral emissivity for metal powder sizes commonly used in AM using a multi-wavelength (MW), FMPI SpectroPyrometer, calibrated within the spectral …
Sensing Optimization Of Thermoplastics And Ceramics Fabricated Through Additive Manufacturing, Cory Marquez
Sensing Optimization Of Thermoplastics And Ceramics Fabricated Through Additive Manufacturing, Cory Marquez
Open Access Theses & Dissertations
The objective of this research is to fabricate and optimize thermoplastic and ceramic materials that can be fabricated for Laser Sintering (LS), Direct Ink Write (DIW), and Fused Filament Fabrication (FFF) 3D printing. The fabrication of High-Density Polyethylene (HDPE) thermoplastic particles into spherical allow for better flowability and packing density for LS printing which results in better printability and an increase in mechanical properties. The fabrication of clay ceramic allows the printability application for DIW with the implementation of an embedded wireless temperature and relative humidity sensor. The use of FFF multi-material printing allowed the capabilities of 3D printing a …
Heat Transfer Of A 1n Thruster In A 2.5u Cubesat Module, Javier Madrid
Heat Transfer Of A 1n Thruster In A 2.5u Cubesat Module, Javier Madrid
Open Access Theses & Dissertations
With the aerospace industry expanding and moving forward with more ambitious missions, small satellites such as CubeSats have proven to be at the forefront of innovation for research satellites. This innovation have introduced complications which if gone unattended can lead to the loss of the satellite; one such complication coming in the form of propulsion heat transfer. This paper presents an investigation into the propagation of heat transfer within a 2.5 CubeSat module when a 1N thruster is fired inside it. This is done by leveraging the equation of heat transfer and comparing results to those simulated by ANSYS. Not …
Study Of Different Heat Treatments And Aging Conditions For Observing Microstructures And Mechanical Properties Of Lpbf Fabricated F357 Alloy, Victor Adrian Medrano Balderas
Study Of Different Heat Treatments And Aging Conditions For Observing Microstructures And Mechanical Properties Of Lpbf Fabricated F357 Alloy, Victor Adrian Medrano Balderas
Open Access Theses & Dissertations
Aluminum F357 is a widely used material for casting in the aerospace and additive manufacturing industry. Heat treatments are commonly applied to some aluminum alloys to modify their properties. With a further study on the aging and performance of the F357 with 3D printing technology, several industries benefit from this; military, automotive, and aerospace are some examples because of the numerous components cast in service. This work presents the mechanical properties of F357 specimens fabricated with EOS technology and subjected to heat treatments. Heat treatment conditions were applied to tensile specimens and tested. Furthermore, the specimens were subjected to artificial …