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Scaled Experiment Investigating Sonomechanically Enhanced Inert Gas Sparging Mass Transfer, Floren Rubio, Leonard J. Bond, Edward Blandford 2017 University of New Mexico

Scaled Experiment Investigating Sonomechanically Enhanced Inert Gas Sparging Mass Transfer, Floren Rubio, Leonard J. Bond, Edward Blandford

Aerospace Engineering Publications

One of the leading advanced reactor concepts is the fluoride salt high temperature reactor (FHR) currently under investigation. This design utilizes a fluoride molten salt, flibe (2 LiF/BeF2), as the primary coolant. One challenge of employing flibe as a coolant is the production and release of tritium. The FHR community is currently investigating various techniques to solve this tritium management challenge. One of the methods investigated is inert gas sparging which has been investigated during the Molten Salt Reactor Experiment (MSRE) in the 1960’s and 1970’s. To enhance the efficiency of this technique, high power ultrasonics can ...


A Comparison Study Of Composite Laminated Plates With Holes Under Tension, Joun S. Kim 2017 California Polytechnic State University, San Luis Obispo

A Comparison Study Of Composite Laminated Plates With Holes Under Tension, Joun S. Kim

Master's Theses and Project Reports

A Comparison Study of Composite Laminated Plates with Holes under Tension

A study was conducted to quantify the accuracy of numerical approximations to deem sufficiency in validating structural composite design, thus minimizing, or even eliminating the need for experimental test. Error values for stress and strain were compared between Finite Element Analysis (FEA) and analytical (Classical Laminated Plate Theory), and FEA and experimental tensile test for two composite plate designs under tension: a cross-ply composite plate design of [(0/90)4]s, and a quasi-isotropic layup design of [02/+45/-45/902]s, each with a single, centered hole of ...


Electron Yield Measurements Of High-Yield, Low-Conductivity Dielectric Materials, Justin Christensen 2017 Utah State University

Electron Yield Measurements Of High-Yield, Low-Conductivity Dielectric Materials, Justin Christensen

All Graduate Theses and Dissertations

Materials exposed to the space plasma environment acquire electric charge, which can have harmful effects if it leads to arcing or electrostatic breakdown of important spacecraft components. In fact, spacecraft charging is the leading environmentally induced cause of spacecraft anomalies. This study focuses on measuring electron yield, a property of materials that describes how many electrons are ejected from a material under energetic electron bombardment, which can vary depending on the energy of incident electrons. Intrinsic electron yield is defined as the average number of electrons emitted per incident electron from an electrically neutral material. The specific aim of this ...


Transient Analysis Of Fracture Initiation In A Coupled Thermoelastic Solid, Louis Milton Brock 2017 University of Kentucky

Transient Analysis Of Fracture Initiation In A Coupled Thermoelastic Solid, Louis Milton Brock

Mechanical Engineering Faculty Publications

An isotropic, thermoelastic solid is initially at rest at uniform (absolute) temperature, and contains a semi-infinite, plane crack. Application of in-plane and normal point forces to each face of the crack causes transient 3D growth. The related problem of discontinuities in temperature and displacement that exist on regions that exhibit dynamic similarity is first considered. Asymptotic expressions, whose inverses are valid near the crack edges for short times, are obtained in integral transform space. These lead to equations of the Wiener–Hopf type for the fracture problem. Analytical solutions are obtained and, upon inversion, subjected to a dynamic energy release ...


Rethinking The Design Of Low-Cost Point-Of-Care Diagnostic Devices, Faith W. Kimani, Samuel M. Mwangi, Benjamin J. Kwasa, Abdi M. Kusow, Benjamin K. Ngugi, Jiahao Chen, Xinyu Liu, Rebecca Cademartiri, Martin M. Thuo 2017 Kiambu District Hospital

Rethinking The Design Of Low-Cost Point-Of-Care Diagnostic Devices, Faith W. Kimani, Samuel M. Mwangi, Benjamin J. Kwasa, Abdi M. Kusow, Benjamin K. Ngugi, Jiahao Chen, Xinyu Liu, Rebecca Cademartiri, Martin M. Thuo

Materials Science and Engineering Publications

Reducing the global diseases burden requires effective diagnosis and treatment. In the developing world, accurate diagnosis can be the most expensive and time-consuming aspect of health care. Healthcare cost can, however, be reduced by use of affordable rapid diagnostic tests (RDTs). In the developed world, low-cost RDTs are being developed in many research laboratories; however, they are not being equally adopted in the developing countries. This disconnect points to a gap in the design philosophy, where parameterization of design variables ignores the most critical component of the system, the point-of-use stakeholders (e.g., doctors, nurses and patients). Herein, we demonstrated ...


Comparison Of Acoustoelastic Lamb Wave Propagation In Stressed Plates For Different Measurement Orientations, Ning Pei, Leonard J. Bond 2017 Iowa State University

Comparison Of Acoustoelastic Lamb Wave Propagation In Stressed Plates For Different Measurement Orientations, Ning Pei, Leonard J. Bond

Aerospace Engineering Publications

High order Lamb waves are investigated for the effects of stress on both symmetrical and anti-symmetrical modes in an aluminum plate for wave propagation and load parallel. Data are compared with those for the case of load and measurement axis perpendicular. It is the S1 mode which exhibits significantly higher sensitivity to stress than other Lamb modes. For aluminum the use of the S1 mode for stress measurement is found to be about six times more sensitive, than bulk waves, for the load-measurement axes parallel case and this compares with about ten times for the case of load-measurement axes perpendicular.


The Shaping Of Things That Are: How Airplane Windows Took Their Shape, Morgan Lopez 2017 Embry-Riddle Aeronautical University

The Shaping Of Things That Are: How Airplane Windows Took Their Shape, Morgan Lopez

Student Works

Have you ever wondered why your airplane's windows are rounded? It is not for aesthetic appeal.

The first commercial jetliner windows' sole purpose was appearance; a squared window afforded an impressive view of the earth, but the view was not without consequence.


Pressure Self-Focusing Effect And Novel Methods For Increasing The Maximum Pressure In Traditional And Rotational Diamond Anvil Cells, Biao Feng, Valery I. Levitas 2017 Iowa State University

Pressure Self-Focusing Effect And Novel Methods For Increasing The Maximum Pressure In Traditional And Rotational Diamond Anvil Cells, Biao Feng, Valery I. Levitas

Aerospace Engineering Publications

The main principles of producing a region near the center of a sample, compressed in a diamond anvil cell (DAC), with a very high pressure gradient and, consequently, with high pressure are predicted theoretically. The revealed phenomenon of generating extremely high pressure gradient is called the pressure self-focusing effect. Initial analytical predictions utilized generalization of a simplified equilibrium equation. Then, the results are refined using our recent advanced model for elastoplastic material under high pressures in finite element method (FEM) simulations. The main points in producing the pressure self-focusing effect are to use beveled anvils and reach a very thin ...


Structural Behavior Of Inflatable, Reinforced, Braided, Tubular Members, Joshua Clapp 2017 University of Maine

Structural Behavior Of Inflatable, Reinforced, Braided, Tubular Members, Joshua Clapp

Electronic Theses and Dissertations

The Hypersonic Inflatable Aerodynamic Decelerator (HIAD) system being developed by the National Aeronautics and Space Administration (NASA) is an inflatable structure composed of multiple, concentric, pressurized tori, load straps, and a thermal protection system. The HIAD overcomes limitations inherent with the use of rigid decelerators since the deployed diameter is much larger than the packed size, which makes it an enabling technology for new opportunities in space exploration. The HIAD is designed to decelerate and protect spacecraft during atmospheric re-entry. The objective of this research was to improve understanding of structural behavior of HIAD components through material testing, structural testing ...


Hazard Assessment Of Meteoroid Impact For The Design Of Lunar Habitats, Herta Paola Montoya, Shirley Dyke, Julio A. Ramirez, Antonio Bobet, H. Jay Melosh, Daniel Gomez 2017 Purdue University

Hazard Assessment Of Meteoroid Impact For The Design Of Lunar Habitats, Herta Paola Montoya, Shirley Dyke, Julio A. Ramirez, Antonio Bobet, H. Jay Melosh, Daniel Gomez

The Summer Undergraduate Research Fellowship (SURF) Symposium

The design of self-sustaining lunar habitats is a challenge primarily due to the Moon’s lack of atmospheric protection and hazardous environment. To assure safe habitats that will lead to further lunar and space exploration, it is necessary to assess the different hazards faced on the Moon such as meteoroid impacts, extreme temperatures, and radiation. In particular, meteoroids pose a risk to lunar structures due to their high frequency of occurrence and hypervelocity impact. Continuous meteoroid impacts can harm structural elements and vital equipment compromising the well-being of lunar inhabitants. This study is focused on the hazard conceptualization and quantification ...


Using High Resolution Images To Investigate Fatigue Crack Initiation Of Alloys At The Microstructural Level, Michael P. Reinhold, Alberto Mello, Michael Sangid 2017 Purdue University

Using High Resolution Images To Investigate Fatigue Crack Initiation Of Alloys At The Microstructural Level, Michael P. Reinhold, Alberto Mello, Michael Sangid

The Summer Undergraduate Research Fellowship (SURF) Symposium

Microstructural features within a material dictate the material’s mechanical behavior and lead to localized strains as the sample is deformed. In order to further understand structural failure, an improved understanding of how microstructural features influence failure is necessary. Fatigue is one common mode of failure for aerospace applications, and a better understanding of the conditions of crack initiation can provide information that ultimately may increase longevity of aerospace systems. This paper investigates the hypothesis that fatigue crack initiation for a cyclically loaded sample is correlated to areas of higher localized strain. The experiment was conducted using a Ti-6Al-4V sample ...


Deployable Antenna For Cubesat, Mackenzie Thomas Lennon, Caleb Andrew Barber, David Matthew Galves 2017 California Polytechnic State University, San Luis Obispo

Deployable Antenna For Cubesat, Mackenzie Thomas Lennon, Caleb Andrew Barber, David Matthew Galves

Mechanical Engineering

This project is a proof-of-concept ground model of a large deployable antenna designed for the small space requirements of CubeSats. This small deployment module is designed to fit a 2 m by 1 m reflective antenna inside a storage volume of with the dimensions 20 cm by 20 cm x 40 cm. The reflector will be deployed to a parabolic shape with the goal of modeling the reflector necessary for high frequency communication. Because this module is designed as a proof-of-concept for the deployable parabolic reflector specifically, no electrical components will be incorporated and will just focus on the deployment ...


Wing Deflection Analysis Of 3d Printed Wind Tunnel Models, Matthew G. Paul 2017 California Polytechnic State University, San Luis Obispo

Wing Deflection Analysis Of 3d Printed Wind Tunnel Models, Matthew G. Paul

Master's Theses and Project Reports

This work investigates the feasibility of producing small scale, low aerodynamic loading wind tunnel models, using FDM 3D printing methods, that are both structurally and aerodynamically representative in the wind tunnel. To verify the applicability of this approach, a 2.07% scale model of the NASA CRM was produced, whose wings were manufacturing using a Finite Deposition Modeling 3D printer. Experimental data was compared to numerical simulations to determine percent difference in wake distribution and wingtip deflection for multiple configurations.

Numerical simulation data taken in the form of CFD and FEA was used to validate data taken in the wind ...


Optimum Design Of Composite Wing Spar Subjected To Fatigue Loadings, Juan Reuben Lazarin 2017 California Polytechnic State University, San Luis Obispo

Optimum Design Of Composite Wing Spar Subjected To Fatigue Loadings, Juan Reuben Lazarin

Master's Theses and Project Reports

Composites are now being incorporated into aircraft designs because of their high strength to weight ratio compared to traditional metal materials. Due to the complexity of the material, composite parts are presently being over designed to satisfy static and fatigue requirements. A greater understanding of composite fatigue behavior will allow for even greater weight savings leading to increased fuel economy. A critical part of an aircraft that is subjected to fatigue bending loads are its wings. The forces acting on the wings include its lift distribution, powerplant, and fuel which can be carried in the wing body. When in flight ...


Study Of Knowledge-Based System (Kbs) And Decision Making Methodologies In Materials Selection For Lightweight Aircraft Metallic Structures, Pashupati R. Adhikari, Reza Mirshams 2017 University of North Texas

Study Of Knowledge-Based System (Kbs) And Decision Making Methodologies In Materials Selection For Lightweight Aircraft Metallic Structures, Pashupati R. Adhikari, Reza Mirshams

Journal of Applied Science & Engineering Technology

This paper presents an overview of knowledge-based system (KBS) in the context of decision making methodologies used in materials selection for the design of light weight aircraft metallic structures. Overall aircraft weight reduction means substantially less fuel consumption and better efficiency. Part of the solution to this problem is to find a way to reduce overall weight of metallic structures in the aircraft. Two distinct multiple criteria decision making (MCDM) methodologies are presented with examples featuring a set of short-listed materials suitable in the design of the structures. Pre-defined constraint values, mainly mechanical properties, are employed as relevant attributes satisfying ...


Study Of Custom Tool Control In Aviation And Aerospace And Selection Of Materials And Manufacturing Process, Ethan C. Rowley 2017 Morehead State University

Study Of Custom Tool Control In Aviation And Aerospace And Selection Of Materials And Manufacturing Process, Ethan C. Rowley

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Business and Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science by Ethan C. Rowley on April 27, 2017.


Analysis Of Metallic Structure With Ultrasonic Nondestructive Evaluation, Carter Sawin 2017 Iowa State University

Analysis Of Metallic Structure With Ultrasonic Nondestructive Evaluation, Carter Sawin

Symposium on Undergraduate Research and Creative Expression

From the first copper tools to modern passenger jets, metals have been the most influential material in our world since their discovery and first development over 9000 years ago. Metals both literally and figuratively support civilizations, and significant failures/defects in them can be catastrophic due to this important role. To prevent failure, engineers use imaging techniques such as Nondestructive evaluation (NDE) to find and compensate for/eliminate harmful flaws like cracks. NDE allows engineers to evaluate and test metal for defects without altering or damaging the metal being tested, and is, therefore, extremely valuable. The main purpose of this ...


Using X-Ray Micro-Ct Scanning To Characterize Cracking In Composites, Rachel Roth 2017 Iowa State University

Using X-Ray Micro-Ct Scanning To Characterize Cracking In Composites, Rachel Roth

Symposium on Undergraduate Research and Creative Expression

Fibrous composites are used throughout the aerospace industry with military, commercial, satellite, and space exploration applications. Composites are desired for their high specific strength and stiffness to weight ratios, as well as their malleability to produce aerodynamically efficient structures. We used computed tomography (CT) to investigate the structural integrity of two small rectangular carbon-fiber composite samples after each underwent unknown amounts of physical stress. Results revealed consistent cracking along the long edges and patterns of cracking through the center of one sample and virtually no cracking in the other sample. The results of this study will help to determine the ...


Unmanned Aircraft System-Based Structural Health Monitoring, Sam Dwyer 2017 Iowa State University

Unmanned Aircraft System-Based Structural Health Monitoring, Sam Dwyer

Symposium on Undergraduate Research and Creative Expression

While many think of unmanned aerial vehicles as only serving military purposes, their scope has widened immensely over recent years into the commercial realm, and even into consumer hands. Using unmanned aircraft systems to diagnose health problems and create risk values can ensure the safety of many expensive complex engineering systems, without the intrusion of human error. Engineered systems, such as space shuttles, infrastructure, airplanes, and even the runways they sit on go through regular fatigue, and need to be health monitored to ensure their safety in continued use. To do this, we attach imaging devices to a variety of ...


Temperature Dependence Of Electromechanical Impedance Based Bond-Line Integrity Monitoring, Prathamesh N. Bilgunde, Leonard J. Bond 2017 Iowa State University

Temperature Dependence Of Electromechanical Impedance Based Bond-Line Integrity Monitoring, Prathamesh N. Bilgunde, Leonard J. Bond

Center for Nondestructive Evaluation Conference Papers, Posters and Presentations

Electromechanical impedance (EMI) is an important technique for bond-line integrity monitoring of adhesively bonded joints in automotive and aerospace structures. In the current work, numerical analysis of temperature sensitivity of the EMI technique is performed. The objective is to detect stiffness reduction of the adhesive in the presence of temperature and external mechanical load. Increase in the operating temperature can degrade the bonded piezoelectric material causing misinterpretation of the EMI data. EMI Signal features are numerically investigated to decouple the effect of load and temperature on the piezoelectric material in the mechanically loaded bonded joint. The computational results indicate higher ...


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