Mechanical Engineering Commons^™

A Miniaturized Spectrophotometric In Situ Ph Sensor For Seawater, Reuben C. Darlington

Graduate Student Theses, Dissertations, & Professional Papers

Since the Industrial Revolution, the world's oceans have absorbed increasing amounts of CO2 and the resultant changes to the marine carbonate chemical system have reduced the pH by > 0.1 units (~ 30%) in surface waters. This acidification of the oceans has many far reaching impacts on marine life and there is great need of quality instrumentation to assess and follow the changing carbonate system. This MIS project aims to develop a low cost pH sensor with high precision and accuracy for open sea measurements with special emphasis on reduced size and cost. Design effort is based on the commercially available …

Additive Manufacturing Of Glass Using A Filament Fed Process, Junjie Luo

Doctoral Dissertations

"There are many scientific and engineering applications of glass including optics, communications, electronics, and hermetic seals, there has been minimal research towards the Additive Manufacturing (AM) of transparent glass parts. The special thermal and optical properties of glasses make them hard to be printed using conventional AM techniques. In this dissertation, two different AM techniques for glass AM were developed, Selective Laser Melting (SLM) and filament fed process.

Semi-transparent parts were printed with SLM process. However, the filament fed process was found to be more robust and promising for printing optically transparent glass parts. Therefore, this dissertation is focused on …

Cyber-Physical Manufacturing Cloud: An Efficient Method Of Building Digital Twin For 3d Printer By Adapting Mtconnect Protocol, Liwen Hu

Masters Theses

"The common modeling of a virtual machine is using an information model to describe the physics of machines. The integration of digital twins into productive cyber-physical cloud manufacturing (CPCM) systems imposes strict requirements such as reducing overhead and saving resources for the systems. In this paper, we investigate a new method for building cloud-based digital twins (CBDT), which can be adapted to the CPCM platform. Our method helps reduce computing resources in the processing center and guarantees the fastest speed of the interactions between the human users and physical machines. We introduce a knowledge resource center (KRC) built on a …

Effect Of Local Magnetic Field Disturbances On Inertial Measurement Units Accuracy, Xavier Robert-Lachaine, Hakim Mecheri, Christian Larue, André Plamondon

Études primaires

Inertial measurement units (IMUs), a practical motion analysis technology for field acquisition, have magnetometers to improve segment orientation estimation. However, sensitivity to magnetic disturbances can affect their accuracy. The objective of this study was to determine the joint angles accuracy of IMUs under different timing of magnetic disturbances of various durations and to evaluate a few correction methods. Kinematics from 12 individuals were obtained simultaneously with an Xsens system where an Optotrak cluster acting as the reference system was affixed to each IMU. A handling task was executed under normal laboratory conditions and imposed magnetic disturbances. Joint angle RMSE was …

Anisotropic Character Of Low-Order Turbulent Flow Descriptions Through The Proper Orthogonal Decomposition, Nicholas Hamilton, Murat Tutkun, Raúl Bayoán Cal

Mechanical and Materials Engineering Faculty Publications and Presentations

Proper orthogonal decomposition (POD) is applied to distinct data sets in order to characterize the propagation of error arising from basis truncation in the description of turbulence. Experimental data from stereo particle image velocimetry measurements in a wind turbine array and direct numerical simulation data from a fully developed channel flow are used to illustrate dependence of the anisotropy tensor invariants as a function of POD modes used in low-order descriptions. In all cases, ensembles of snapshots illuminate a variety of anisotropic states of turbulence. In the near wake of a model wind turbine, the turbulence field reflects the periodic …

Fifty-Plus-Year Postflight Analysis Of First Fluid Experiment Aboard A Spacecraft, Mark M. Weislogel, Yongkang Chen, William J. Masica, Fred J. Kohl, Robert D. Green

Mechanical and Materials Engineering Faculty Publications and Presentations

This year marks the 55th anniversary of the first fluid physics experiment performed aboard a spacecraft during the Mercury-Atlas 7 mission. Since then, NASA has conducted over 80 fluids physics experiments aboard a variety of spacecraft, many of which have enhanced the understanding of large-length-scale capillary phenomena relevant to liquid management in the weightless state. As both celebration and demonstration, the Mercury-Atlas 7 fluids experiment is revisited in light of the current understanding of large-length-scale capillary fluidics. Employing a modern numerical tool, a rich variety of experimental outcomes are discovered that were not observed during the flight experiment. Interestingly, experimental …

Three Dimensional Finite Element Model For Residual Stresses In Parts Manufactured By Slm And Ebm, Jesus Gerardo Reyes Schuldes

Open Access Theses & Dissertations

Ongoing research efforts in industry and academia have a focus on optimal build parameters that lead to suitable mechanical properties with minimum defects in parts manufactured by powder bed fusion additive manufacturing technologies, such as Electron Beam Melting (EBM) and Selective Laser Melting (SLM). Additional and significant resources, including energy, time, and money are spent as a result of obligatory post-manufacturing heat and/or mechanical treatment to ensure optimum mechanical properties. One intrinsic fault in these technologies, which contributes to the need for treatment processes after part fabrication, is the creation of residual stresses during these processes. Residual stresses remain in …

Modeling The Effects Of Manufacturing Geometric Imperfections In The Buckling Analysis Of Three-Dimensional Structures, Juan Carlos Salcido

Open Access Theses & Dissertations

Reticulated three-dimensional structures follow design practices based on the common assumption that joints are either rigid, or pinned. However, the actual non-linear behavior of the jointing system interaction is required to be incorporated into the analysis of the structure to accurately predict its buckling stability. Besides, currently, there is a concern on how manufacturing imperfections of these jointing systems affect the global behavior of three-dimensional structures. This Dissertation incorporates and captures the effect that manufacturing geometric imperfections in the fir-tree jointing system produce in the non-linear buckling behavior of three-dimensional structures.

To understand the effect that initial manufacturing imperfections of …

Design & Analysis Of A 500 Lbf Liquid Oxygen And Liquid Methane Rocket Engine, Daniel Eduardo Vargas

Open Access Theses & Dissertations

The rapid growth in demand for spacecraft technologies has spawned a need for a variety of new and innovative research. The utilization of liquid oxygen (LOX) and liquid methane (LCH4) in rocket engines have played an important role in space exploration efforts to promote missions to Mars with in-situ resource utilization for propellant production. This will allow the production of fuel needed to come back to Earth making the overall mission more cost effective by enabling larger usable mass.

The Center for Space Exploration and Technology Research has focused its efforts to developing Liquid Oxygen (LOX) and Liquid Methane (LCH4) …

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 …

Integrative Experiences Through Modeling And Simulation Of Mechatronic Systems, Mileta Tomovic, Cynthia Tomovic, Vukica M. Jovanovic, Cheng Y. Lin, Nan Yao, Petros J. Katsioloudis

Engineering Technology Faculty Publications

Learning is integrative lifelong process which requires continuous refreshing of old material and learning new material. This principle holds also for student experiences during their undergraduate studies. Students learn new material throughout their studies, and they may or may not have opportunity to use the material in different context and at different levels. As a result some of the acquired knowledge may be forgotten by the time student graduates or it may not be placed in the context of the overall program outcomes, thus material presented may not seem to have relevance to student's career. An effective method to address …

Developing A Curriculum For Marine Mechatronics Technicians, Vukica M. Jovanovic, Petros J. Katsioloudis, Ana Djuric, Mileta Tomovic, Thomas B. Stout

Engineering Technology Faculty Publications

A growing trend within the U.S. Navy is to streamline operations by deploying ships with less sailors, who are more highly skilled technicians that are trained to do a wide array of jobs. Modern ships also include various automated systems that require more highly skilled technicians for maintenance. Outdated warship designs are now being replaced with industrial grade automation equipment. Such equipment is being used in warships that encounter harsher environments than what exists in the civilian industry. Hence, there is a need for training in regards to industrial grade automation equipment for military and civilian ship repair partners. Marine …

Behavioral Responses Of Sub-Adult Atlantic Sturgeon (Acipenser Oxyrinchus Oxyrinchus) To Electromagnetic And Magnetic Fields Under Laboratory Conditions, Andrew Mcintyre Iii

Theses and Dissertations

Electromagnetic fields (EMF) produced by high voltage (HV), submarine transmission cables leading from offshore wind energy generation facilities could affect foraging or migratory behaviors of electro-receptive fishes, including endangered Atlantic Sturgeon. However, no published studies have quantitatively evaluated the possible behavioral effects of EMF exposure on sturgeon during residence in coastal waters. This study evaluated behavioral responses by sub-adult Atlantic Sturgeon to electromagnetic and magnetic fields under controlled laboratory conditions. Fabricated EMF generators were used to emulate a range of field EMF conditions that migratory fishes could encounter in proximity to submarine HV sources. Sensor arrays and digital video recorders …

Thermomechanical Modeling Of Polymerica Actuators, Qianxi Yang

LSU Doctoral Dissertations

In this dissertation, the application of smart polymers as actuators was investigated, with focuses on shape memory polymers and twisted-then-coiled artificial muscles. Thermomechanical models have been developed for various polymeric actuators, so as to facilitate interpretation of the underlying mechanisms and to provide guidance for future design. The classical one-way shape memory effect in amorphous shape memory polymers was first reproduced. The amorphous shape memory polymer was treated as a frozen-phase matrix with active-phase inclusions embedded in it. A phase evolution law was proposed from the physics perspective and the Mori-Tanaka approach was used to predict the effective mechanical properties. …

Analytical Solutions And Multiscale Creep Analysis Of Functionally Graded Cylindrical Pressure Vessels, Jasem Amjad Ahmed

LSU Doctoral Dissertations

This study deals with the time-dependent creep analysis of functionally graded thick-cylinders under various thermal and mechanical boundary conditions. Firstly, exact thermoelastic stress, and iterative creep solutions for a heat generating and rotating cylindrical vessel made of functionally graded thermal and mechanical properties are proposed. Equations of equilibrium, compatibility, stress-strain, and strain-displacement relations are solved to obtain closed-form initial stress and strain solutions. It is found that material gradient indices have significant influences on thermoelastic stress profiles. For creep analysis, Norton’s model is incorporated into rate forms of the above-mentioned equations to obtain time-dependent stress and strain results using an …

Osteogenic Potential Of Poly (L-Lactic Acid) Scaffolds Prepared By Thermally Controlled Methods On Human Adipose Derived Stem Cells, Harish Chinnasami Shanmugam

LSU Doctoral Dissertations

Thermally Induced Phase Separation (TIPS) method was used to make porous three-dimensional PLLA scaffolds. The effect of imposed thermal profile during freezing of the PLLA in dioxane solution on the scaffold was characterized by their micro-structure, porosity (%), pore-sizes distribution and mechanical strength. The porosity (%) decreased considerably with increasing concentrations of PLLA in the solution, while a decreasing trend was observed with increasing cooling rates. The mechanical strength increases with increase in PLLA concentration and also with increase in the cooling rate for both types of solvents. Therefore, mechanical strength was increased by higher cooling rates while the porosity …

Design Of Electrical Layout Of Offshore Wind Farms, Shirshak K. Dhali, Mahidhar Nandigam

Electrical & Computer Engineering Faculty Publications

The cost and efficiency of offshore wind farms are determined by a variety of factors which include the type of electrical system (AC or DC), transmission length, transmission voltage, rated power, wind turbine type, farm topology, and wind speed. Since the design variable space is large for such problems, computational optimization is necessary to find an optimal solution. This paper discusses a design methodology to determine the optimal values of components to minimize the cost of an offshore wind farm. The cost, loss, reliability models, and the application of geometric programing for optimization of the layout and configuration of an …

Metal Cutting And Manufacturing Economics Project For Freshmen, Hüseyin Sarper, Nebojsa I. Jaksic, Linda Vahala

Electrical & Computer Engineering Faculty Publications

This paper describes a laboratory experiment and a team project to teach manufacturing concepts to new students. This project is one of two team projects of 1.5 credit portion of a two-credit course in exploration of engineering and technology. This course teaches students skills they need late and teamwork is a major skill that they acquire. They organize into a group with specialized responsibilities for the purpose of calculating the total production time and cost of a manufactured part using turning, drilling, and milling operations. Students also learn or improve spreadsheet skills while performing data entry and necessary machining calculations. …

Novel Design Of Nanostructured Material For Advanced Energy Conversion And Storage Devices, Wangwang Xu

LSU Master's Theses

Nowadays, the fast-increasing energy demand for efficient, sustainable and environmentally-friendly energy storage devices remains a significant and challenging issue. Lithium ion batteries (LIBs) have been widely used as commercial energy devices in portable electronics and also shown great promise in upcoming large scale applications due to their advantages of environmental safety, efficiency in energy delivering and light weight. However, due to their limited capacity, energy densities and cycle ability, LIBs still need further improvement to expand their applications to a larger field, especially electric vehicle (EVs) and hybrid electric vehicles (HEVs), in which energy storage devices with large capacity and …

Heat And Mass Transfer In A Cylindrical Heat Pipe With Idealized Porous Lining, Pramesh Regmi

LSU Master's Theses

Many devices use heat pipes for cooling. They can be of different cross-sectional shapes and can range from 15 m long to 10 mm. In this work, the heat and mass transfer in a cylindrical heat pipe is modelled. The heat pipe is lined with a wick next to the wall. The wick consists of straight capillaries that run the whole length of the pipe and radially aligned capillaries that span the width of the wick. The capillaries are filled with a partially wetting liquid, and the center of the pipe is filled with its vapor. The radial capillaries are …

Sensitivity Analysis Method To Address User Disparities In The Analytic Hierarchy Process, Marie Ivanco, Gene Hou, Jennifer Michaeli

Mechanical & Aerospace Engineering Faculty Publications

Decision makers often face complex problems, which can seldom be addressed well without the use of structured analytical models. Mathematical models have been developed to streamline and facilitate decision making activities, and among these, the Analytic Hierarchy Process (AHP) constitutes one of the most utilized multi-criteria decision analysis methods. While AHP has been thoroughly researched and applied, the method still shows limitations in terms of addressing user profile disparities. A novel sensitivity analysis method based on local partial derivatives is presented here to address these limitations. This new methodology informs AHP users of which pairwise comparisons most impact the derived …