Open Access. Powered by Scholars. Published by Universities.®

Mechanical Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

University of Texas at El Paso

Discipline
Keyword
Publication Year

Articles 1 - 30 of 195

Full-Text Articles in Mechanical Engineering

Direct Write 3d Printing Of Functional Ceramics, Jorge Angel Diaz Jan 2019

Direct Write 3d Printing Of Functional Ceramics, Jorge Angel Diaz

Open Access Theses & Dissertations

Humidity sensors are used in many industries and are important for ensuring quality and safety. Ceramic sensors are preferred because of their quick response time, ability to withstand high temperatures and excellent Chemical and mechanical stability. The manufacturing world has been moving toward additive manufacturing which is a form of synthesizing 3D tangible layer by layer in witch minimal waste is produced. Additive manufacturing also is known as 3D printing has opened new possibilities to design engineers by giving them design freedom and access to the layers of a part to allow embedded sensors. There is a category of ceramics ...


Small Satellite Development At Utep, Emily Herzog Jan 2019

Small Satellite Development At Utep, Emily Herzog

Open Access Theses & Dissertations

The small satellite industry has seen tremendous growth in recent years. A CubeSat is a particular type of standardized small satellite that follows the CubeSat specifications. These specifications define the structural, testing, and operational requirements of the satellite. This standard facilitates cheaper design, integration, and launch of satellites, allowing smaller organizations to participate in the normally costly area of space exploration.

The University of Texas at El Paso has recognized the opportunity and has begun developing several CubeSats. The two that are the topic of this Thesis are called Orbital Factory II (OFII) and Orbital Factory X (OFX). An on-orbit ...


Tailoring The Mechanical And Optical Properties Of Silicon-Niobium-Nitride Composite Coatings, Cristian Orozco Jan 2019

Tailoring The Mechanical And Optical Properties Of Silicon-Niobium-Nitride Composite Coatings, Cristian Orozco

Open Access Theses & Dissertations

Nitride nanocomposite thin films have generated significant attention as a result of their robust mechanical properties, excellent triobology, and good chemical (corrosion) stability. Due to their excellent hardness and high wear resistance NbN coatings have found use in a wide variety of applications such as the coating of cutting tools and to strengthen the surface mechanical properties of superconducting cavities. The mechanical properties of NbN can be further improved through mixing with Si3N4, leading to the formation of a nanocomposite structure. NbN-Si3N4 nanocomposite coatings have been actively studied due to their high hardness, high elastic modulus, and high resistance to ...


Compressive And Rheological Deformation Analysis Of Large Area Pellet-Fed Material Extrusion 3d Printed Parts In Relation To In Situ Thermal Imaging, Eduardo Meraz Trejo Jan 2019

Compressive And Rheological Deformation Analysis Of Large Area Pellet-Fed Material Extrusion 3d Printed Parts In Relation To In Situ Thermal Imaging, Eduardo Meraz Trejo

Open Access Theses & Dissertations

In large area pellet extrusion additive manufacturing, the temperature of the substrate just prior to the deposition of a new subsequent layer has an effect on the overall structure of the part. Warping and cracking occur if the substrate temperature is below a specific threshold, but also deformation and deposition adhesion failure occur if the substrate temperature is above a certain threshold just prior to deposition of a new layer. Currently, Big Area Additive Manufacturing (BAAM) machine users mitigate this problem by trial and error, which is costly and may result in decreased mechanical properties, monetary losses and time inefficiencies ...


Impact Of Temperature And Screw Speed On Material Meso-Structure And Tensile Strength In Large Area Pellet-Fed Additive Manufacturing, Xavier Jimenez Guzman Jan 2019

Impact Of Temperature And Screw Speed On Material Meso-Structure And Tensile Strength In Large Area Pellet-Fed Additive Manufacturing, Xavier Jimenez Guzman

Open Access Theses & Dissertations

Evolution in additive manufacturing, specifically in material extrusion, has resulted in large-scale machines capable of extruding thermoplastic-matrix composite materials in higher volumes to fabricate products for large-scale applications. As with small- and medium-scale material extrusion, the properties of the final product often correlate directly with the bevy of print parameters employed. The current research was performed to evaluate the effects of the screw speed and temperature on an ABS 20%wt. carbon fiber thermoplastic processed on a Big Area Additive Manufacturing (BAAM, Cincinnati Inc) machine. Five screw speeds (50, 150, 250, 350 and 400 rpm) and three extruder temperature profiles ...


Materials Characterization In The Development Of Combustion-Based Methods For Synthesis Of Niobium Silicides, Edgar Maguregui Jan 2019

Materials Characterization In The Development Of Combustion-Based Methods For Synthesis Of Niobium Silicides, Edgar Maguregui

Open Access Theses & Dissertations

The use of characterization techniques is essential for a better understanding of novel manufacturing processes and for investigating how the process parameters affect the products. Mechanically activated self-propagating high-temperature synthesis (MASHS) is an attractive method for the production of high-temperature structural materials. In the present work, it was used to fabricate Nb5Si3 compound and Nb5Si3/Nb composites. It has been shown that for mechanical activation of Nb/Si mixtures, a planetary ball mill is more effective than a shaker ball mill used in prior research on MASHS of Nb5Si3. The influence of mixture composition and experimental parameters, such as milling ...


Pressureless Sintering Of Zirconium Diboride Obtained By Combustion Synthesis, Gabriel Llausas Jan 2019

Pressureless Sintering Of Zirconium Diboride Obtained By Combustion Synthesis, Gabriel Llausas

Open Access Theses & Dissertations

Magnetohydrodynamic (MHD) direct power generation has the potential to significantly increase the thermal efficiency of coal fired power plants. Materials for MHD electrodes should have high melting points, high electrical and thermal conductivities, and excellent thermal shock and corrosion resistance. Zirconium diboride (ZrB2), which belongs to the class of ultra-high temperature ceramics (UHTC), is a promising material for this application. Mechanically activated self-propagating high-temperature synThesis (MASHS) is an attractive method for its fabrication. Previous studies have shown that zirconium diboride can be fabricated from inexpensive oxides of zirconium and boron (ZrO2 and B2O3) using magnesium as a reducing agent and ...


Development Of Actuators Using Material Extrusion Additive Manufacturing With Embedded Shape Memory Alloy Wire, Alfonso Fernandez Jan 2019

Development Of Actuators Using Material Extrusion Additive Manufacturing With Embedded Shape Memory Alloy Wire, Alfonso Fernandez

Open Access Theses & Dissertations

Over the past several decades, the advancements in Additive Manufacturing (AM) technologies have opened a wide variety of applications where AM can be used. Some examples of these advancements are the introduction of automatic wire embedding capabilities, the introduction of multi-material processing and the printing of thermoplastic elastomers. With the availability of these advancements, it is now possible to create spark-free, dust-free actuation mechanisms for applications where it is crucial that no spark is generated (i.e. space shuttle fuel valve).

In this research, a Lulzbot TAZ 6 desktop material extrusion system was utilized to print parts out of Plasticized ...


Investigating Using Titanium Zirconium Molybdenum For Additively Manufacturing Aerospace Components, Justin Hunter Vanhoose Jan 2019

Investigating Using Titanium Zirconium Molybdenum For Additively Manufacturing Aerospace Components, Justin Hunter Vanhoose

Open Access Theses & Dissertations

Mankind throughout history has possessed an innate characteristic to explore, migrating to new frontiers.The requirement for this travel is most broadly associated with the need to pursue more resources. Rockets have been used as a means of weapons since the Sung Dynasty in the thirteenth empire and have now been integrated for travel/transport. The sophistication of rocketry and propulsion has reached a level to where it is plausible that mankind will be a multi-planetary species. The space industry has grown significantly with the advancement of the sophistication of these rocket technologies. However, a specific challenge to overcome in ...


Structures And Daq System For The Lox/Lch4 500 And 2000 Lbf. Rocket Engines, Rachel Pilgrim Jan 2019

Structures And Daq System For The Lox/Lch4 500 And 2000 Lbf. Rocket Engines, Rachel Pilgrim

Open Access Theses & Dissertations

With the progression of space exploration and research, new alternative fuels and fuel combinations have been discovered. The ability to produce methane from Mars' atmosphere and oxygen from Mars' regolith has led to the two becoming a great alternative propellant combination for rocket propulsion systems. To further advance LOX/LCH4 propulsion systems, a 500 and 2000 lbf rocket engine were designed and manufactured and are to be launched from the MIRO cSETR Technology Research and Innovation Acceleration Park (tRIAc) in Fabens, Texas for data collection and analysis. The objective of this thesis is to give a thorough overview of the ...


Design And Experimental Study Of A High Pressure And Supercritical Methane-Oxygen Burner, A S M Arifur Rahim Chowdhury Jan 2018

Design And Experimental Study Of A High Pressure And Supercritical Methane-Oxygen Burner, A S M Arifur Rahim Chowdhury

Open Access Theses & Dissertations

Directly heated supercritical oxy-fuel power cycles have potential to offer a higher thermal efficiency and lower pollutant emissions compared to existing power cycles. Recent thermodynamic analysis of the cycle performed by several groups including the UTEP-Air Liquide research team show that combustion in the vicinity of 300 bar pressure and 1000-1400 K temperature allows for relatively high system efficiencies while operating within the limit of practical combustor materials. However, the realization of directly heated supercritical power cycle requires combustion systems be designed to operate in supercritical conditions and at temperature far below the blowout limit of conventional flames (above 1500 ...


Fracture Mechanics Of Heterogeneous Composites, Md Fazle Rabbi Jan 2018

Fracture Mechanics Of Heterogeneous Composites, Md Fazle Rabbi

Open Access Theses & Dissertations

The increasing application of composite materials due to their ubiquitous advance in terms of mechanical and thermal properties has brought attention to the fracture mechanics of the materials possessing heterogeneity. Recent investigations have focused on the micro- and macro-mechanism of fracture in heterogeneous composites (HCs). In this study, the fracture mechanics of the two HCs: Polymer bonded explosive (PBX) simulant and hot mixed asphalt (HMA) are evaluated on the macroscopic scale. It is an interest of Sandia National Laboratory to examine the fracture resistance of PBXs, particularly those of varying composition and subjected to aging. In this research, a batch ...


Implementing Large Eddy Simulation To Numerical Simulation Of Optical Wave Propagation, Diego Alberto Lozano Jimenez Jan 2018

Implementing Large Eddy Simulation To Numerical Simulation Of Optical Wave Propagation, Diego Alberto Lozano Jimenez

Open Access Theses & Dissertations

In this study, we want to simulate long-range laser propagation in atmospheric turbulence. The numerical simulations are carried out to study the impact of strong atmospheric turbulence in spatial, temporal, and related spectral domains. The first section of this study will be concerned with modeling this numerical simulation in Kolmogorov and non-Kolmogorov spectrum. To validate our numerical simulation, we will compare the statistical parameter to theoretical approximation in both Kolmogorov and non-Kolmogorov spectrums. Once the code is validated, we want to integrate Large Eddy Simulation (LES) turbulence modeling. LES simulations allowa us to study strong fluid turbulence and can predict ...


Design Of Robotic Tram Unit For Field Data Collection, Quetzalcoatl Mendoza Rosas Jan 2018

Design Of Robotic Tram Unit For Field Data Collection, Quetzalcoatl Mendoza Rosas

Open Access Theses & Dissertations

Satellite remote sensing is the most applied method for detection and measurement of electromagnetic energy and its interaction with Earth surface. the analysis of the data acquired can provide important information with uses in areas as like weather forecasting, military intelligence and environmental and resources location. Due to the great distance from where the samples are taken and even with the most sophisticated sensor it is impossible to have an exactly replica of the Earth surface. As a result, scientist analyze imagery where a single pixel can be the representation of a 30 by 30 meters area of land. This ...


Constitutive Model Development For Additive Manufacturing, Diana Berenice Montes Jan 2018

Constitutive Model Development For Additive Manufacturing, Diana Berenice Montes

Open Access Theses & Dissertations

Additive manufacturing (AM) is known worldwide for revolutionizing the development of three-dimensional modeling by reducing the time and increasing the precision of parts. For Powder Bed Fusion research is necessary to reduce concerns in residual stress, porosity and cracking in AM parts. A constitutive model was created in Abaqus to validate material properties of 3D printed Al 6061. Finite element analysis was performed to investigate how properties may affect in the modification of parameters to reduce printing imperfections. Research was made as well in polylactic acid properties for material extrusion to explore its behavior for creep and relaxation. Properties were ...


Development Of A Desktop Material Extrusion 3d Printer With Wire Embedding Capabilities, Jose Francisco Motta Jan 2018

Development Of A Desktop Material Extrusion 3d Printer With Wire Embedding Capabilities, Jose Francisco Motta

Open Access Theses & Dissertations

Printed circuit boards (PCB) have been widely used as a permanent solution for generating complex circuitries to power electronic devices. Over the years, PCB boards have proved to be reliable when powering electronic devices. However, when fabricating a printed circuit board, one must outsource to fabricate the boards when in prototype phase. Therefore, the risk of intellectual property theft and long lead time is an issue. The objective of this Thesis is to develop a hybrid multi-tool desktop material extrusion 3D printer that allows for easy integration (modularity) of tools to generate multi-functional 3D printed components.

The addition of an ...


Data-Driven Predictive Framework For Modeling Complex Multi-Physics Engineering Applications, Arturo Schiaffino Bustamante Jan 2018

Data-Driven Predictive Framework For Modeling Complex Multi-Physics Engineering Applications, Arturo Schiaffino Bustamante

Open Access Theses & Dissertations

Computational models are often encountered in multiple engineering application, such as structural design, material science, heat transfer and fluid dynamics. These simulations offer the engineers the capability of understanding complex physical situations before putting them to practice, either through experimentation or prototyping. The current advances in computational sciences, hardware architecture, software development and big data technology, have allowed the construction of sturdy predicting frameworks for analyzing a wide array of natural phenomena across different disciplines, either through the implementation of statistical methods, such as big data, and uncertainty quantification, or through high performance computing of a numerical model. The objective ...


Combustion Joining Of Regolith Tiles For The Construction Of Launch And Landing Pads On The Moon And Mars, Robert Edwin Ferguson Jan 2018

Combustion Joining Of Regolith Tiles For The Construction Of Launch And Landing Pads On The Moon And Mars, Robert Edwin Ferguson

Open Access Theses & Dissertations

Combustion-based methods are attractive for space manufacturing because the use of chemical energy stored in reactants dramatically decreases the required external energy input. Recently, a sintering technique has been developed for converting lunar/Martian regolith into ceramic tiles, but it is unclear how to build a reliable launch/landing pad from these tiles with small amounts of energy and materials. Here the feasibility of joining regolith tiles using self-propagating high-temperature reactions between two metals powders is explored. Combustion of a 1:1 molar aluminum/nickel mixture placed in a gap between two tiles, made of JSC-1A lunar regolith simulant, was ...


An Adaptive Creep Modeling Approach Using Metamodeling, Mohammad Shafinul Haque Jan 2018

An Adaptive Creep Modeling Approach Using Metamodeling, Mohammad Shafinul Haque

Open Access Theses & Dissertations

Recent drives to increase the efficiency of existing fossil energy power plants and the development of Advanced Ultrasupercritical power plants, have led to designs with steam pressures above 4000 psi and temperatures exceeding 1400°F. The complexity of the applied thermo-mechano chemical boundary conditions makes it critically important to consider creep and creep related failures. A primary concern to FE practitioners is the determination of which constitutive models are the "best", capable of reproducing the mechanisms expected in an intended design accurately; as well as what experimental data sets are proper or "best" to use for fitting the constitutive parameters ...


Predictive Modeling On The Piezoelectric Properties Of 3d Printed Functional Nanocomposites Using The Data Analytics Approach, Md Didarul Islam Jan 2018

Predictive Modeling On The Piezoelectric Properties Of 3d Printed Functional Nanocomposites Using The Data Analytics Approach, Md Didarul Islam

Open Access Theses & Dissertations

This paper presents research done on prediction modeling using a data analytics approach to determine various factors affecting the piezoelectric properties of the 3D printed pressure sensors. Previously, the material extrusion 3D printing technique was used to fabricate pressure sensors composed of multiwall carbon nanotubes (CNT), barium titanate (BT), and polyvinylidene fluoride (PVDF) using simple fabrication and low-cost methods. This sensor produced a voltage output of 725 mV (0.13 pC/N) which is enough for pressure sensing applications. However, a holistic study to determine impacts of all factors was not carried out in the previous model. In this study ...


Tungsten Doping Induced Superior Mechanical Properties Of Hafnium Oxide For Energy Applications, Ann Marie Uribe Jan 2018

Tungsten Doping Induced Superior Mechanical Properties Of Hafnium Oxide For Energy Applications, Ann Marie Uribe

Open Access Theses & Dissertations

Hafnium oxide, or hafnia, is a high temperature refractory material with good electrical, chemical, optical, and thermodynamic properties. The effects of dopants have been widely studied, especially after the discovery of ferroelectricity induced in hafnia thin films. While attractive and used in the opto-electronic, memory devices, and semiconductor industries, there is a lack in the literature on enhancing the mechanical properties of hafnium oxide, specifically through doping it with tungsten, another material of interest particularly for future high temperature device applications. Thus, this work aimed to grow hafnia thin films doped with varying amounts of tungsten. The samples were grown ...


Experimental Laser Powder Bed Fusion System For Difficult To Process Metallic Materials, Syed Zia Uddin Jan 2018

Experimental Laser Powder Bed Fusion System For Difficult To Process Metallic Materials, Syed Zia Uddin

Open Access Theses & Dissertations

The focus of this research was twofold, such as development of defect free fabrication parameters for laser powder bed fusion (LPBF) processing of crack prone or difficult to process metallic materials, and study of the temperature dependence of emissivity for some commonly used metal alloy powders in LPBF process. The later objective extends to the implementation of multiwavelength (MW) pyrometer technology for in situ true surface temperature measurement in LPBF process. LPBF is an additive manufacturing (AM) process capable of layer-by-layer manufacturing by successive laser melting of each layer according to CAD data. AM manufacturing has the inherent advantages of ...


Testing Of A 1n Af-M315e Thruster, Daniela Ivette Aguilar Jan 2018

Testing Of A 1n Af-M315e Thruster, Daniela Ivette Aguilar

Open Access Theses & Dissertations

The Center for Space Exploration and Technology Research (cSETR) at the University of Texas at El Paso (UTEP) is currently pursuing various space propulsion and small satellite projects. One of these projects is called Orbital Factory X (OFX), which mission is to design a 2U Cube-Satellite (Cube Sat) with 4 green mono-propellant thrusters along with multiple micro-cathode arc thrusters. A CubeSat is a small-scale version of a satellite that is usually placed in orbit for near earth missions. However, they have a relative short life and limited maneuverability due to their limited source of power and restricted payload. Now, technologies ...


Behavior Of Sandwich Composite Cores Under Extreme Conditions, Carlos Daniel Garcia Perez Jan 2017

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 Jan 2017

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 ...


The Design, Construction And Operation Of System To Analyze The Decomposition Gases Of Af-M315e, Jonathan Alejandro Valenzuela Brok Jan 2017

The Design, Construction And Operation Of System To Analyze The Decomposition Gases Of Af-M315e, Jonathan Alejandro Valenzuela Brok

Open Access Theses & Dissertations

With the current trend of aerospace organizations towards developing green monopropellant, the key priority is to eliminate the use of highly dangerous monopropellants, such as hydrazine. In that vein, one of the best candidates to replace hydrazine is a monopropellant known as AF-M315E. AF-M315E was developed by the Air Force and is currently being advanced by NASA and private corporations for use on various satellite platforms, with NASA looking to launch a test satellites part of their Green Propellant Infusion Mission (GPIM), Raytheon providing support on the Missile Defense Agency's Network Centric Airborne Defense Element (NCADE) program and Department ...


Design And Development Of A Foil Application Tool For A Foil Embedding Process In The Multi3d Manufacturing System, Betty Elizabeth Mckenzie Jan 2017

Design And Development Of A Foil Application Tool For A Foil Embedding Process In The Multi3d Manufacturing System, Betty Elizabeth Mckenzie

Open Access Theses & Dissertations

Additive manufacturing (AM) encompasses different technologies, including material extrusion 3D printing, a technology commonly referred to as fused deposition modeling (FDM), which is the focus of the work described in this manuscript. Additive manufacturing is a growing technology with many applications in numerous fields from the air force to medical offices. FDM is a process that uses thermoplastics, in this case polycarbonate (PC), where the PC is heated and selectively dispensed in a layer-by-layer process to create a 3D printed part. Currently, FDM systems have advantages over subtractive manufacturing or machining because cavities and other components (e.g., microchips, valves ...


Design Of A 2000 Lbf Lox/Lch4 Throttleable Rocket Engine For A Vertical Lander, Israel Lopez Jan 2017

Design Of A 2000 Lbf Lox/Lch4 Throttleable Rocket Engine For A Vertical Lander, Israel Lopez

Open Access Theses & Dissertations

Liquid oxygen (LOX) and liquid methane (LCH4) has been recognized as an attractive rocket propellant combination because of its in-situ resource utilization (ISRU) capabilities, namely in Mars. ISRU would allow launch vehicles to carry greater payloads and promote missions to Mars. This has led to an increasing interest to develop spacecraft technologies that employ this propellant combination.

The UTEP Center for Space Exploration and Technology Research (cSETR) has focused part of its research efforts to developing LOX/LCH4 systems. One of those projects includes the development of a vertical takeoff and landing vehicle called JANUS. This vehicle will employ a ...


Microstructure And Mechanical Properties Of Sputter-Deposited Nanocrystalline W1-Ymoyo3 Thin Films, Gabriel Lopez Jan 2017

Microstructure And Mechanical Properties Of Sputter-Deposited Nanocrystalline W1-Ymoyo3 Thin Films, Gabriel Lopez

Open Access Theses & Dissertations

Currently, there is a wide-spread interest in the design and development of indium (In) free transparent conductive oxides (TCOs) for utilization in photovoltaics and optoelectronics. Tungsten oxide (WO3)-based materials are being explored for their utilization in solar cells, photo-electrochemical cells (PECs), electrochromic (EC) "smart windows," information displays, variable reflectance mirrors, and photo-detector materials. Designing ternary compounds or composite/hybrid structures coupled with tailoring the nano-architectures of WO3-based materials has been considered to be attractive develop potential candidates with enhanced performance. In this context, in this Thesis work, an attempt is made to prepare W-Mo-O nanocomposite films, which can be ...


Structural And Mechanical Characterization Of Nanocrystalline Tungsten And Tungsten-Based Alloy Thin Films For Extreme Environment Applications, Gustavo Martinez Jan 2017

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 ...