Mechanical Engineering Commons^™

Comprehensive Finite Element Modeling Of Ti-6al-4v Cellular Solids Fabricated By Electron Beam Melting, Edel Arrieta

Open Access Theses & Dissertations

Additive manufacturing permits the fabrication of cellular metals which are materials that can be highly customizable and possess multiple and extraordinary properties such as damage tolerance, metamorphic and auxetic behaviors, and high specific stiffness. This makes them the subject of interest for innovative applications. With interest in these materials for energy absorption applications, this work presents the development of nonlinear finite element models in commercial software platforms (MSC Patran/Nastran) that permit the analysis of the deformation mechanisms of these materials under compressive loads. In the development of these models, a detailed multiscale study on the different factors affecting the response …

Characterization Of Electrically Conductive Inks In Simulated Space Environment, Kazi Md Masum Billah

Open Access Theses & Dissertations

Increasing numbers of satellite missions necessitate a standalone power supply with self-recovery capabilities in case of failure in the space environment. A self-repairing kit was developed with the capabilities to repair the damaged solar array by dispensing conductive inks. Dispensing of conductive materials using direct writing technology to the space environment not only repairs damaged electronic components but also demonstrates the possibilities of manufacturing in outer space. For earth application, properties of direct writing inks have been evolved. In space application, direct writing inks or conductive inks have some issues such as outgassing, vapor pressure, curing etc.Therefore, having the properties …

Organic-Inorganic Graphite And Transition Metal Dichalcogenide Based Composites For 3d Printing, Jorge Alfredo Catalan Gonzalez

Open Access Theses & Dissertations

This project was multipronged to help fuse together topics of additive manufacturing and two-dimensional (2D) layered materials, and studying the mechanical and electrical properties of the composites produced. The composites are made from the thermoplastic polymer acting as a matrix and the graphite and 2D transition metal dichalcogenides (TMDs) serving as the filler or reinforcement. Different concentrations of TMD's were added to the matrix to study the effect of composition on the mechanical and electrical properties. To shed insights into the mechanical properties, test coupons were produced as "dog bone" structures for tensile testing using the ASTM D638 type 5 …

The Development Of A Data Acquisition And Control System For Rocket Propulsion Research, Javier Chaparro

Open Access Theses & Dissertations

The MIRO Center for Space Exploration Technology Research (cSETR) at the University of Texas at El Paso (UTEP) has developed the Technology Research and Innovation Acceleration Park (tRIAC) in Fabens, Texas. This facility has been established in order to meet new research demands for experimental testing of Liquid Oxygen (LOX)/Liquid methane (LCH4) propulsion systems. Within this facility, a vertical test stand capable of measuring up to 3,000lbf will be constructed for main engine testing of the JANUS and DAEDALUS vehicle programs.

In order to meet challenges of precise remote system operation and data acquisition during engine testing, cSETR designed and …

On-Orbit Autonomous Repair: Systems Design And Project Management Of The Orbital Factory Ii Cube-Satellite, Mike Louis Everett

Open Access Theses & Dissertations

In 2016, a group of faculty, staff and students from the University of Texas at El Paso submitted a formal entry to the ULA CubeCorp competition to launch a 1U Cube Satellite into Orbit. In September of 2016, the team was awarded a launch opportunity to a prestigious GTO orbit to test and validate electrically conductive printing on within the Van Allen Radiation belts. This Dissertation is focused upon the management plan and specific decision that were implemented to accomplish this goal within a one year time frame and on a conservative budget.

In 2018 this satellite will launch aboard …

First Level Design And System Design Of Janus Liquid Oxygen-Liquid Methane Lander, Jahir Fernandez

Open Access Theses & Dissertations

Taking humans to space has always been a fantastic feat, but taking humans to another planet in our solar system is the new goal. Technology has come a long way and with that, so has our knowledge of space and what can be done with current technology to accomplish our goal. These technologies allow for a more efficient space system to transport future astronauts using liquid oxygen and liquid methane (LO2-LCH4) as propellants. This combination of propellants, LO2-LCH4, brings a variety of benefits. One of the main advantages is that they can be recovered or created from local resources, using …

Behavior Of Sandwich Composite Cores Under Extreme Conditions, Carlos Daniel Garcia Perez

Open Access Theses & Dissertations

The use of composite structures for diverse applications have become of great interest for scientists and engineers thanks to the advantages that they may offer in comparison to conventional materials. In the case of sandwich composite structures, its mechanical properties can be tailored according to the necessities through the correct selection of a core and facesheets. In combination, this "new" material will have superior properties compared to traditional materials such as steel and aluminum. For arctic exploration, a core with low moisture absorption, low density, and resistance to extreme, low temperatures is desirable for this type of application. This Thesis …

Design Of A 1 Megawatt Heat Input Direct Power Extraction System For Advanced Topping Cycles, Brian Matthew Lovich

Open Access Theses & Dissertations

Power development has become a standard for living; as such more efficient and cleaner methods are desired. One such method is that of the direct power extraction system utilizing Magnetohydrodynamic properties. This paper will discuss the combustor designed and developed for a direct power extraction system at the 1 MW heat input range. A short history of the power systems utilized with a focus on the direct power class will be conducted in the first chapter to give insight into the benefits of using the direct power system. Then a literature review the fundamentals of direct power systems will be …

Structural And Mechanical Characterization Of Nanocrystalline Tungsten And Tungsten-Based Alloy Thin Films For Extreme Environment Applications, Gustavo Martinez

Open Access Theses & Dissertations

Extreme environments associated with nuclear applications often results in degradation of the physical, mechanical and thermo-mechanical properties of the materials. Tungsten (W) exhibits unique physical and mechanical properties, which makes tungsten a good candidate for nuclear applications; however, intrinsic W exhibits low fracture toughness at all temperatures in addition to a high ductile to brittle transition. In the present work, nanocrystalline W, W-Y and W-Mo alloys were nanoengineered for nuclear applications. Nanocrystalline tungsten coatings with a thickness of ~1 µm were deposited onto Silicon (100) and Sapphire (C-plane) using RF and DC sputtering techniques under various growth conditions. Yttrium content …

Hardware Development And Testing For Lox/Lch4 Rocket Engine, Pedro Nunez

Open Access Theses & Dissertations

The University of Texas at El Paso (UTEP) Center for Space Exploration and Technology Research (cSETR) has focused its research efforts on developing LOX/LCH4 propulsion systems. As part of the Janus Sub-orbital vehicle program, UTEP is developing a 2000 lbf throttleable rocket engine (Chrome X). The first iteration of this engine design will be geared for further optimization towards a flight engine. Components like electric motors, valves, and sealants have been selected to achieve throttle ability and sealing of the engine. These components play a crucial part on the engine to be able to have a successful firing. As part …

Development Of The Thermal Wire Embedding Technology For Electronic And Mechanical Applications On Fdm-Printed Parts, Daniel Abraham Marquez

Open Access Theses & Dissertations

Additive Manufacturing (AM) has increased in popularity and attracted much attention from many fields such as automotive, aviation, aerospace, and even the fashion industry. Since the early 2000s, Fused Deposition Modeling (FDM) technologies have been the most popular in the AM world ("Wohlers Talk" Popularity of FDM). These technologies have been mainly used for building parts for prototype and structural type of applications such as a fixture for components or a housing for mechanisms.

With the current state of the FDM technologies, the functionality of the parts that are printed are limited to the applications listed before or simply just …

Structural Design Of Liquid Oxygen/Liquid Methane Robotic Lander Janus, Mariana Chaidez

Open Access Theses & Dissertations

As the attempt to send humans to Mars has gained momentum in the last decade, the need to find alternative propellants that are safer, less toxic, and yields a better performance has become apparent [1]. Liquid methane and oxygen have emerged as a suitable alternative. In addition, the incorporation of liquid methane/liquid oxygen into the propulsion system has demonstrated an increase in engine performance, as well as a reduction in the volume, size and complexity of the propulsion system. In an attempt to further understand the technologies that are possible to develop using liquid oxygen (LO2) and liquid methane (LCH4), …

G-Code Generation For Multi-Process 3d Printing, Callum Peter Bailey

Open Access Theses & Dissertations

Since the inception of stereolithography in the 1980s, interest in 3D printing has exploded, with desktop 3D printers now commercially accessible to the general public. In recent years, next-generation multifunctional technologies have been developed, which combine 3D printing with other technologies such as wire embedding, foil embedding, CNC machining, and robotic component placement, enabling complex parts to be made on a single multifunctional machine.

However, the complexity of these integrated processes exceeds the capabilities of established design tools. To this end, this Thesis aims to develop a multi-functional design solution that can automatically generate final control code for next-generation multifunctional …

Design Optimization Of Sandwich Core, Mohammad Tauhiduzzaman

Open Access Theses & Dissertations

Ultralight sandwich structures comprising of low-density core with stiff facings have attracted significant research interest for their considerable weight saving applications. The aircraft industries are focusing on decreasing the structural mass to lower the manufacturing and operating costs. Design analysis of the sandwich cores using finite element analysis has been developed as a promising concept to feature sandwich structures with maximum strength, stiffness, and reduced weight. To obtain multifunctional behavior of sandwich panels, a profound investigation of geometrical and mechanical properties in the transverse plane is required because it is very susceptible to any kind loadings. Structural optimization is one …

Damage Tolerance And Assessment Of Unidirectional Carbon Fiber Composites, Mark David Flores

Open Access Theses & Dissertations

Composites are beginning to be used in a variety of different applications throughout industry. However, certification and damage tolerance is a growing concern in many aerospace and marine applications. Although compression-after-impact have been studied thoroughly, determining a damage tolerance methodology that accurately characterizes the failure of composites has not been established. An experimental investigation was performed to study the effect of stacking sequence, low-velocity impact response, and residual strength due to compression and fatigue. Digital Image Correlation (DIC) captured the strains and deformation of the plate due to compression. Computational investigations integrated non-destructive techniques (C-Scan, X-Ray) to determine the extent …

Flame Front Structures Studies Of Highly Turbulent Reacting Flow Over A Backward Facing Step Using Khz Oh-Ch Planar Laser Induced Fluorescence, Arturo Acosta-Zamora

Open Access Theses & Dissertations

In recent years, there has been a greater move in the scientific and political community to increase combustion efficiency and reduce emission levels; for this reason, it is crucial to gain a better understanding of combustion. Experimental work at relevant conditions and the data generated from these is needed in order to gain a better understanding of combustion; this data may also be used for validation and further refinement of computational models and simulations. The improvement of optical combustion diagnostics systems has opened new ways to explore these combustion processes. The testing of a high intensity turbulence combustion system is …

Magnesium-Based Combustion Synthesis Of Advanced Materials For Energy And Space Applications, Armando Delgado

Open Access Theses & Dissertations

As energy problems become more challenging, interest in low-energy-consuming methods for the fabrication of materials increases. Combustion synThesis is one such method because it is sustained by reaction heat release instead of external energy input. In the present work, combustion synThesis approaches are applied to the production of construction materials from lunar and Martian regolith and to the fabrication of magnesium silicide (Mg2Si), a promising thermoelectric material for high-temperature applications. In both cases, magnesium (Mg) was used as one of the main reactants and similar experimental approaches were employed.

Recently, it has been proposed to use combustion of lunar regolith …

Yttria Rich Tbcs As Candidates For Cmas Resistant Top Coats, Juan Jose Gomez

Open Access Theses & Dissertations

State of the art thermal barrier coatings (TBC) commonly made of 7-8 wt. % yttria stabilized zirconia (7YSZ) are used in modern gas turbines to generate a thermal protection to the underlying super alloy components. TBCs allow higher operating temperatures for hot gas path components, thus, generating higher engine efficiency. The infiltration of molten glassy mineral deposits composed of CaO-MgO-Al2O3-SiO2 (CMAS) represents one of the major threats in reducing performance and service life in aero and land based gas turbine engines. The CMAS deposits are ingested into the engine carried commonly in sand, runways debris, fly ash and volcanic ash. …

Manufacturing And Mechanics Of Polymer Matrix Composites, Md Shariful Islam

Open Access Theses & Dissertations

Fiber-reinforced composite materials are widely used in the aerospace and automobile industries. Their strength-to-weight and stiffness-to-weight ratios make them suitable to be used in spacecraft, especially as cryogenic tank materials. One of the focus of this dissertation is to investigate the application of woven carbon and Kevlar® fiber composites as cryogenic tank materials. Tensile, bending and short beam shear tests are performed on rectangular specimens at room temperature and after cryogenic exposure (-196°C). It is found that the mechanical properties of these composite materials do not degrade significantly due to cryogenic exposure. It is observed that the failure mode took …

Design Of A Thermal Management System For An Oxy-Methane Direct Power Extraction Combustor, Jad Gerges Aboud

Open Access Theses & Dissertations

The overarching goal of this Thesis is to present the design of a thermal management system for an oxy-methane direct power extraction combustor. The design is initiated by performing a 2D analysis on the combustor geometry and then using these results in a 3D model. This is done by using results for heat transfer coefficient and temperatures found from the 2D simulation and importing these to the 3D model. The approach used here couples the combustion process, heat transfer through the chamber wall, and fluid flow behaviors in order to observe the thermal characteristics of the combustor during operation. This …

Structural, Dielectric, And Ferroelectric Characterization Of Lead-Free Calcium-Cerium Co-Doped Batio3 Ceramics, Juan Alberto Duran

Open Access Theses & Dissertations

Structure, morphology, and regulation of the dielectric properties via close-composition intervals is demonstrated for variable-cerium, constant-calcium co-doped barium titanate (Ba0.80Ca0.20CeyTi1-yO3; y=0.0-0.25; referred to BCCT). The effect of variable Ce-content on the structure and dielectric properties of BCCT is investigated. X-ray diffraction spectra confirms the studied samples are mainly in BT tetragonal phase with a small secondary phase detected as CaTiO3 in BCCT for y = 0.20 and 0.25. However, the lattice parameter reduction was evident with increasing Ce-content. Composition-driven dielectric constant leap (4,000-5,500) was observed from intrinsic BCT to BCCT for (y = 0.0-0.04). The temperature dependent dielectric constant showed …

Design And Experimental Investigation Of An Oxy-Fuel Combustion System For Magnetohydrodynamic Power Extraction, Manuel Johannes Hernandez

Open Access Theses & Dissertations

A general consensus in the scientific and research community is the need to restrict carbon emissions in energy systems. Therefore, extensive research efforts are underway to develop the next generation of energy systems. In the field of power generation, researchers are actively investigating novel methods to produce electricity in a cleaner, efficient form. Recently, Oxy-Combustion for magnetohydrodynamic power extraction has generated significant interest, since the idea was proposed as a method for clean power generation in coal and natural gas power plants. Oxy-combustion technologies have been proposed to provide high enthalpy, electrically conductive flows for direct conversion of electricity. Direct …

Design And Performance Evaluations Of A Lo2/Methane Reaction Control Engine, Aaron Johnson

Open Access Theses & Dissertations

Liquid oxygen (LOX) and liquid methane (LCH4) are a propellant combination viewed as a potential enabling technology for spacecraft propulsion. Reasons why LOX/LCH4 is being used as an alternative propellant source include: it is less toxic than other propellants, it has the possibility to be harvested on extraterrestrial soil, LCH4 has a higher energy density than liquid hydrogen (LH2; commonly used on vehicle main engines), and LOX/LCH4 has comparable performance to other well-known propellant combinations. Through the continued partnership between the National Aeronautics and Space Administration (NASA) and the University of Texas at El Paso (UTEP) a LOX/LCH4 reaction control …

Modeling And Testing Of Functional Materials For Energy System Applications, Hasanul Karim

Open Access Theses & Dissertations

Energy efficiency is one of the key concerns addressing the problem of global warming. Numerous research has been going on in order to improve the efficiency of energy conversion systems to reduce the polluted emission in the atmosphere. One of the approach is monitoring and maintaining the critical parameters of operation such as temperature to ensure the desired reactions, however, the harsh environment present in these systems makes the use of current temperature sensing solutions such very challenging to implement. Wireless temperature sensors are getting increasing attention as a potential solution, however, the need of energy storage devices such as …

Development And Testing Of Oxygen/Methane Torch Igniter Technologies For Propulsion Systems, Luis Eduardo Sanchez

Open Access Theses & Dissertations

The development and testing of an oxygen/methane torch ignition system as well as the evaluation process of the system are presented with the purpose of characterizing the properties and performance of methane as a fuel in a propulsion system. The experimental approach to this Dissertation entails the development and testing of a swirl torch igniter under conditions that may be seen when feeding propellant from the main storage tanks: combinations of gaseous and liquid oxygen and methane. The experimental goal of this Dissertation is to display the range of operability of the igniter technology presented leading to stable and consistent …

Mechanically Activated Combustion Synthesis Of Molybdenum Borosilicides For Ultrahigh-Temperature Structural Applications, Alan Alberto Esparza Hernandez

Open Access Theses & Dissertations

The desire to improve the efficiency of power generation gas-turbines has led to a relentless quest for new, ultrahigh-temperature structural materials to replace the current nickel-based superalloys. These materials have reached the maximum allowable operating temperature determined by the melting temperature of these alloys, which is about 1150 °C. These materials could be replaced by molybdenum silicides and borosilicides based on Mo5SiB 2 (T2) phase due to their high melting point and mechanical properties. A major challenge, however, is to simultaneously achieve high oxidation resistance and acceptable mechanical properties at elevated temperatures. One novel approach to improve these properties is …

Creating Multi-Functional G-Code For Multi-Process Additive Manufacturing, Efrain Aguilera Jr

Open Access Theses & Dissertations

Additive manufacturing (AM) started over thirty years ago and with it a manufacturing revolution that moves industrial production into the personal home. With recent interest shifting into multi-functional parts fabricated through AM technologies, unified systems are being developed. Merging different manufacturing technologies into one single machine is a challenge but undergoing research has shown promise in the development of multi-functional systems. Concurrent work is being done in the software, automation, and hardware aspect of multi-functional systems. An effort to use industry compatible Computer Aided Design (CAD) software to design multi-functional parts including circuits, micro-machining, and foil embedding then exporting and …

Modeling And Characterization Of Piezoelectric Based Multifunctional Structures, Ricardo Martinez Hernandez

Open Access Theses & Dissertations

Continuous monitoring of high pressure and high temperature in energy system applications has been a developing research area in today’s energy sector. Multifunctional materials have the potential to provide real-time monitoring of structures where temperature and pressure sensing is critical to its performance and efficiency. In this study, multifunctional materials are studied by embedding piezoelectric materials with two ongoing technologies, woven fabric composites and additive manufacturing (AM). The AM technology allows the flexibility of embedding a sensor within the structure, all while not compromising the mechanical performance requirements. The “smart parts” are fabricated modifying the standard additive manufacturing process, using …

Microstructural Characterization Of High Velocity Oxy Fuel Coatings Of Inconel 718 And Iron Aluminides, Ana Cecilia Rios Ibanez

Open Access Theses & Dissertations

Thermal spray guns are used today to deposit metallic powders as homogeneous and durable coatings with low porosity onto metals. The objective is to improve their wear resistance and their corrosion resistance in order to withstand conditions such as abrasion and erosion. This can improve the life of turbines, generators and such devices in environments found in ultra-supercritical coal-fired (AUSC) boilers, steam turbines and gas turbines (Mohammed & Cabrera, 2014). Industries like manufacturing, automobile and especially in the sustainable energy area, have used this technique to improve component characteristics, extend product life, increase performance as well as reduce production and …

Design Of A 500 Lbf Liquid Oxygen And Liquid Methane Rocket Engine For Suborbital Flight, Jesus Eduardo Trillo

Open Access Theses & Dissertations

Liquid methane (LCH4)is the most promising rocket fuel for our journey to Mars and other space entities. Compared to liquid hydrogen, the most common cryogenic fuel used today, methane is denser and can be stored at a more manageable temperature; leading to more affordable tanks and a lighter system. The most important advantage is it can be produced from local sources using in-situ resource utilization (ISRU) technology. This will allow the production of the fuel needed to come back to earth on the surface of Mars, or the space entity being explored,making the overall mission more cost effective by enabling …