Engineering Commons^™

Fatigue Testing And Data Analysis Of Welded Steel Cruciform Joints, Alina Shrestha

LSU New Orleans Theses and Dissertations

In this study, ABS Publication 115, “Guidance on Fatigue Assessment of Offshore Structures” is briefly reviewed. Emphasis is on the S-N curves based fatigue assessment approach of non-tubular joints, and both size and environment effects are also considered. Further, fatigue tests are performed to study the fatigue strength of load-carrying and non-load-carrying steel cruciform joints that represent typical joint types in marine structures. The experimental results are then compared against ABS fatigue assessment methods, based on nominal stress approach, which demonstrates a need for better fatigue evaluation parameter. A good fatigue parameter by definition should be consistent and should correlate …

Smaller Spacecraft For Education And Space Research, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint presentation created by Professor Bob Twiggs titled "Smaller spacecraft for education and space research" from May 14, 2013.

Middle Atmosphere Temperature Results From A New, High-Powered, Large-Aperture Rayleigh Lidar, Leda Sox, Vincent B. Wickwar, Joshua P. Herron

Utah Space Grant Consortium

In June–July 2012, observations were carried out using the recently upgraded, large-aperture, Rayleigh-scatter lidar system located at the Atmospheric Lidar Observatory (ALO) on the campus of Utah State University, in Logan, UT (41.7 N, 111.8 W). This time period was significant because it enabled us to observe the annual temperature minimum in the upper mesosphere-lower thermosphere region. The data collected during the campaign were analyzed for temperatures between ~70–109 km. The results above ~95 km are the first obtained with a Rayleigh-scatter lidar, extending the technique well into the lower thermosphere. A great deal of variability from night-to-night is evident …

Monte Carlo Uncertainty Analysis For Photothermal Radiometry Measurements Using A Curve Fit Process, Kyle Horne, Austin Fleming, Heng Ban

Utah Space Grant Consortium

Photothermal Radiometry (PTR) has become a popular method to measure thermal properties of layered materials. Much research has been done to determine the capabilities of PTR, but with little uncertainty analysis. This study performs a Monte Carlo uncertainty analysis to quantify uncertainty of film diffusivity and effusivity measurements, presents a sensitivity study for each input parameter, compares linear and logarithmic spacing of data points on frequency scans, and investigates the validity of a 1-D heat transfer assumption.

Establishing Mission Requirements Based On Consideration Of Aircraft Operations, Robert A. Mcdonald

Aerospace Engineering

The design requirements for a next-generation commercial aircraft can do much to secure its fate as a success or failure. New aircraft are often designed to meet or surpass the capabilities of an existing aircraft they are intended to replace. However, in the case of unconventional aircraft, this could lead to significant overdesign resulting in nonviable concepts. Instead, a method of analyzing observed aircraft use is presented with the intent of establishing a set of requirements based on replacing aircraft utility instead of capability. Two aircraft in the commercial fleet are used as example cases, and launch customers for each …

Section Abstracts: Aeronautical And Aerospace Sciences

Virginia Journal of Science

Abstracts of the Aeronautical and Aerospace Sciences Section for the 91st Annual Virginia Journal of Science Meeting, May 2013

Analysis And Mitigation Of The Cubesat Dynamic Environment, Steve M. Furger

Master's Theses

A vibration model was developed for CubeSats inside the Poly-Picosatellite Orbital Deployer (P-POD). CubeSats are fixed in the Z axis of deployers, and therefore resonate with deployer peaks. CubeSats generally start fixed in the X and Y axes, and then settle into an isolated position. CubeSats do not resonate with deployers after settling into an isolated position. Experimental data shows that the P-POD amplifies vibration loads when CubeSats are fixed in the deployer, and vibration loads are reduced when the CubeSats settle into an isolated position. A concept for a future deployer was proposed that isolates CubeSats from the deployer …

End-Of-Life Management Of Crystalline Silicon Photovoltaic Module, Jun-Ki Choi

Mechanical and Aerospace Engineering Faculty Publications

PV manufacturing has been growing over the past 10 years and further annual growth of 15% is expected until 2020. A study on positioning a grand plan for solar power shows how vast PV arrays and other renewable energies can provide significant amount of electricity and total energy needs by 2050. Various new PV technologies have been introduced in the market and existing technologies have undergone further development. How all these developments will affect the fate of the end-of-life PV modules is uncertain. In addition, the market price of some rare earth materials utilized in the manufacturing of the various …

Application Of Archimedes In Three Dimensions And To Solid Mechanics, Jonathan David Aziz

Renée Crown University Honors Thesis Projects - All

ARCHIMEDES is a computerized learning system that has helped Syracuse University students overcome the challenges of Engineering Statics since 2009. Its success has motivated application of ARCHIMEDES to three dimensional problems and to problems in Solid Mechanics. Other learning software was investigated before seven Solid Mechanics problems were written for ARCHIMEDES. A 3D graphical interface was developed and evaluated by a field test of student volunteers. Student preferences for various features in 3D learning software were obtained. It is clear from student responses that having a 3D scene to manipulate improves visualization of the problem, mitigating the ambiguity of a …

Analysis Of Damage In Laminated Architectural Glazing Subjected To Wind Loading And Windborne Debris Impact, Mahesh S. Shetty, Jun Wei, Lokeswarappa R. Dharani, Daniel S. Stutts

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Wind loading and windborne debris (missile) impact are the two primary mechanisms that result in window glazing damage during hurricanes. Wind-borne debris is categorized into two types: small hard missiles such as roof gravel, and large soft missiles representing lumber from wood-framed buildings. Laminated architectural glazing (LAG) may be used in buildings where impact resistance is needed. The glass plies in LAG undergo internal damage before total failure. The bulk of the published work on this topic either deals with the stress and dynamic analyses of undamaged LAG or the total failure of LAG. The pre-failure damage response of LAG …

Deutsche Luftshiffahrts-Aktiengesellschaft: Rediscovering The World’S First Airline, Michael Sloan

Bridgewater Review

No abstract provided.

Application Of Non-Local Approaches For Predicting The Response Of V-Notch Under Thermomechanical Fatigue Loading, Trung Nguyen

HIM 1990-2015

The topic of this thesis is the construction of a formula to approximate stress-strain responses at notches under thermomechanical fatigue (TMF) loading. The understanding of material behavior of the V-notched component which experiences TMF is important to the mechanical industries where V-notched structures are often utilized. In such applications, it is crucial that the designers be able to predict the material behavior; therefore, the purpose of this research is to examine and to model the precise effects a stress concentration will have on a specimen made of a generic Ni-base superalloy. The effects of non-isothermal loading will be studied, and …

Numerical Simulation Of Fracture Of A Nano-Paper Coated E-Glass/Polyester Composite With Thermal Damage, Zachary Graham

HIM 1990-2015

Aerospace research for next-generation travel increasingly focuses on the use of advanced composites to reduce weight and cost while retaining strength. One subset of materials with great potential is based on the combination of resin matrix and glass-fiber reinforcement. This research explores the application of a candidate nanopaper coating with a given composite. Prior research applied a set of given heat fluxes to the top surface of the composite for a set of given periods of time, and subsequently performed a 3-point flexural test to determine the elastic modulus for both the coated and uncoated composite for all of the …

Strategically Minded Dynamic Analysis Of Strategic Flight Bat Maneuvers, Marie Kaspryzk

HIM 1990-2015

CATD was not only adequate for analyzing the pursuit of erratically moving prey but also worked well when analyzing the pursuit of prey that remained stationary. It cannot be fully concluded that bats utilize the CATD strategy to successfully capture erratically flying prey. The angle remains relatively constant but does not exhibit a zero change in angle as by definition. The large forces experienced by the bat were seen when the bat began to rotate its body about its pitch axis or when the bat made a large turn. Moments were seen specifically when the bat began to bank into …

The Application Of Advanced Composites For The Construction Of Commercial Transport Aircraft, Mark D. Severson

Graduate Student Works

This individual Capstone project examined and evaluated current industry methods of testing, certification, and maintenance of advanced composite materials for the construction of commercial transport aircraft and the FAA regulations governing their use. The project critically compared and contrasted existing FAA standards and regulations governing the testing, certification, and maintenance of advanced composites for commercial transport aircraft structural applications with current industry practices to determine whether there were any areas of conflict between the two in order to accept or reject that current testing, certification, and maintenance procedures for advanced composites used in primary and secondary commercial transport aircraft structures …

Supersonic Turbine Cascade Studies Using Computational Fluid Dynamics And Water Table Experiments, Shelby E. Nelson

Honors College Theses

Design engineers use a variety of tools to perform calculations and to aid in the design process. For example, engineers designing gas turbines, specifically the aerodynamicists, use a combination of hand calculations, experimental data, and complex numerical codes to simulate air flow around each blade. Aerodynamicists designing gas turbines must predict the locations of the shocks to locate inefficiencies in the flow. In this thesis, three methods of calculating the shock angles are compared: analytical, experimental, and computational. Three different airfoil shapes are tested: a rectangular flat plate, a supersonic diamond, and a turbine airfoil. Cascade tests of the airfoil …

Hydrodynamic Impact Analysis And Testing Of An Unmanned Aerial Vehicle, Isabel Bird

Doctoral Dissertations and Master's Theses

Analysis and testing have been conducted to assess the feasibility of a small UAV that can be landed in the water and recovered for continued use. Water landings may be desirable in a number of situations, for example when testing UAVs outside of the territorial waters of the US to avoid violating FAA regulations. Water landings may also be desirable when conducting surveillance missions in marine environments. Although the goal in landing is to have the UAV lightly set down on the water, rough seas or gusty winds may result in a nose-in landing where the UAV essentially impacts the …

Investigation Of A Lagrangian-Point Propellant Depot Rendezvous Approach For An Interplanetary Mission To Mars, Joshua W. Ehrlich

Doctoral Dissertations and Master's Theses

This thesis investigates the feasibility of a refueling station for a beyond Earth orbit (BEO) mission. The propellant depot is located at the L₂ -Lagrangian point within the Earth-Moon system. This investigation determines if a refueling mission will reduce propulsive energy requirements necessary for Earth departure of a BEO-vehicle to achieve an interplanetary transfer to Mars. Furthermore, this research presents a trade study which identifies approximate total requirements for a direct and rendezvous mission to Mars as well as the necessary fuel masses to complete each approach. This analysis provides conclusive information in determining the benefits in utilizing a …

Design And Testing Of Digitally Manufactured Paraffin Acrylonitrile-Butadiene-Styrene Hybrid Rocket Motors, Jonathan M. Mcculley

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Hybrid motors that employ non-toxic, non-explosive components with a liquid oxidizer and a solid hydrocarbon fuel grain have inherently safe operating characteristics. The oxidizer is blown though the solid fuel where it is combusted through a nozzle to produce thrust. This research investigated the combination of Acrylonitrile-butadiene-styrene impregnated with paraffin wax as the solid fuel component burned with nitrous oxide. The paraffin provides an enhanced regression rate over ABS; however, it lacks structural integrity and combustion efficiency. Multiple fuel grains with various ABS-to-Paraffin mass ratios were fabricated and burned with nitrous oxide. Analytical predictions for end-to-end motor performance and fuel …

Catalytic Decomposition Of Nitrous Oxide Monopropellant For Hybrid Motor Ignition, Matthew D. Wilson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nitrous oxide (N₂O), a commonly-used industrial gas, is also often used as a rocket motor oxidizer. It has been used in both hybrid rocket motors (using a solid fuel and a liquid oxidizer) and liquid rocket engines (using liquid fuel and oxidizer).

As a liquid form, nitrous oxide is highly stable, but in vapor form it can be decomposed, releasing large amounts of heat as it dissociates into nitrogen and oxygen. This project investigates using the energy from decomposing nitrous oxide to ignite a hybrid or liquid rocket. Such a system would be practical in rocket …

Spin Stability Of Sounding Rocket Secondary Payloads Following High Velocity Ejections, Weston Mcclain Nelson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Auroral Spatial Structures Probe (ASSP) mission is a sounding rocket mission studying the effects of solar energy on space weather. ASSP requires the high speed ejection (up to 50 m/s) of 6 secondary payloads to gather the required data. The scientific instruments on the secondary payloads require that the payloads are stable in flight with coning angles of less than 5º, where the coning angle is the amount the payload is allowed to “wobble” about its spin axis. The secondary payloads are also required to have their spin axes aligned with 25º of the local magnetic field lines. Current …

The Effect Of Navigation State Selection On Fuel Dispersions For Powered Lunar Descent, Jessica Thornley Anderson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A Monte Carlo simulation is developed to study the performance of the closed-loop guidance, navigation, and control (GN&C) system of a lunar lander in powered descent. The simulation includes six-degrees-of-freedom dynamics, an extended Kalman filter, guidance based upon modified Apollo methods, an attitude control system, and several different types of sensors. Sensors included in the sensor suite include accelerometers, gyroscopes, a star camera, an altimeter, a velocimeter, and a radio navigation system. The simulation is used to examine the effects of sensor errors and the number of navigation states on total fuel use.

Error Modeling And Analysis Of Star Cameras For A Class Of 1u Spacecraft, David M. Fowler

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As spacecraft today become increasingly smaller, the demand for smaller components and sensors rises as well. The smartphone, a cutting edge consumer technology, has impressive collections of both sensors and processing capabilities and may have the potential to fill this demand in the spacecraft market. If the technologies of a smartphone can be used in space, the cost of building miniature satellites would drop significantly and give a boost to the aerospace and scientific communities.

Concentrating on the problem of spacecraft orientation, this study sets ground to determine the capabilities of a smartphone camera when acting as a star camera. …

Development Of The Multiple Use Plug Hybrid For Nanosats (Muphyn) Miniature Thruster, Shannon Dean Eilers

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Multiple Use Plug Hybrid for Nanosats (MUPHyN) prototype thruster incorporates solutions to several major challenges that have traditionally limited the deployment of chemical propulsion systems on small spacecraft. The MUPHyN thruster offers several features that are uniquely suited for small satellite applications. These features include 1) a non-explosive ignition system, 2) non-mechanical thrust vectoring using secondary fluid injection on an aerospike nozzle cooled with the oxidizer flow, 3) a non-toxic, chemically-stable combination of liquid and inert solid propellants, 4) a compact form factor enabled by the direct digital manufacture of the inert solid fuel grain. Hybrid rocket motors provide …

Power Efficient Restart-Capable Acrylonitrile Butadiene Styrene-Based Arc Ignition For Hybrid Rocket Motors, Nathan R. Inkley

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Hybrid rocket ignition has historically involved either dangerous energetic materials or inefficient and failure-prone plasma sources. The vast majority of such systems cannot sup- port multiple restart cycles, thus limiting the applicability of hybrid rockets–especially for in-space propulsion. During research investigating its use as a fuel for hybrid rockets, it was discovered that Acrylonitrile Butadiene Styrene (ABS) plastic possesses unique electrical breakdown characteristics. During a properly designed breakdown event, application of a strong electric field induces a high-temperature arc along the surface of the ABS, concurrent with rapid production of hydrocarbon vapor. This behavior forms the basis of a novel …

Optimization Of Induced-Power From Dynamic Inflow Theory With Realistic Constraints, Chad File

All Theses and Dissertations (ETDs)

Finite-state induced-inflow theory is used to develop an analytic formulation for general performance of the lifting rotor with arbitrary loading. The theory incorporates conventional blade-element theory for blade lift and provides the integrated loads and the induced-power of the rotor in terms of an arbitrary number of rotor controls such as conventional collective and cyclic pitch as well as higher harmonic radial and azimuthal pitch. The theory provides the basis for a classical quadratic optimization with realistic constraints that is applied to determine minimum induced-power for a variety of available control combinations, rotor trim constraints, and operating conditions. The findings …

Design Considerations And Requirements For In-Flight Refueling Of Unmanned Vehicles, Ian R. Mcandrew, Kenneth Witcher

Publications

The need to refuel in-flight has become a significant part of military strategy for air forces to work at further distances from safe shores. The use of Unmanned Vehicles is increasing and expected to be the principal part of military deployment. This paper will address the concepts and requirements for applying refueling unmanned vehicles in a military context for supporting fixed and rotor aircraft. Design aspects of human factors in the process are considered, reviewed and solutions proposed to allow for the first generation of designs to be developed. Furthermore, the practical and operational limitations will be addressed as part …

Orbital Debris Removal Technologies: A Hybrid Electrodynamic Tether And Ion Beam Shepherd Satellite Design For Fuel Efficient Contactless Debris Removal, JöRn Mumme

Doctoral Dissertations and Master's Theses

Space debris poses a serious threat to humanities efforts at space exploration as well as the expanding uses for earth-orbiting satellites. This thesis investigates the proposed technologies for the debris's removal both large and small. Focus is applied to the large debris removal technologies since the small size category is dominated by the ORION laser system. Furthermore, the large debris objects pose the most destructive threat upon impact to satellites. Electrodynamic tethers (EDT) as well as their control strategies, ion-beam shepherds (IBS), and tradition thruster methods are investigated for effectiveness and feasibility. Hybrid combinations of these technologies are investigated in …

Comm-Components Of Link Equation, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs on "Comm-Components of Link Equation" from April 10, 2013.

Broncoblade: An Open Source Wind Turbine Blade Analysis Tool, Alex R. Quinlan

Masters Theses

This thesis reports the development and validation of BroncoBlade, a horizontal axis wind turbine analysis tool. BroncoBlade prepares finite element models and integrates them with an aeroelastic simulator. Analysis results for the SNL100-00 baseline blade are evaluated against reference results published by Sandia National Laboratories. Variations on the SNL100-00 blade incorporating carbon fiber are compared to the baseline blade.