Structures and Materials Commons^™

Structural Micrometeoroid And Radiation Shielding For Interplanetary Spacecraft, Jared Allen Ruekberg

Master's Theses

This paper focused on two significant space forces that can affect the success of a spacecraft: the radiation and micrometeoroid environments. Both are looked at in the context of the region of space between Earth and Mars. The goal was create reference environments, to provide context to results of environmental modeling, and to provide recommendations to assist in early design decisions of interplanetary spacecraft. The radiation section of this report used NASA's OLTARIS program to generate data for analysis. The area of focus was on the radiation effects for crewed missions, therefore effective dose equivalent was the metric used to …

Hybrid Rocket Motor Scaling Process, Joseph B. R. Vanherweg

Master's Theses

Hybrid rocket propulsion technology shows promise for the next generation of sounding rockets and small launch vehicles. This paper seeks to provide details on the process of developing hybrid propulsion systems to the academic and amateur rocket communities to assist in future research and development. Scaling hybrid rocket motors for use in sounding rockets has been a challenge due to the inadequacies in traditional boundary layer analysis. Similarity scaling is an amendment to traditional boundary layer analysis which is helpful in removing some of the past scaling challenges. Maintaining geometric similarity, oxidizer and fuel similarity and mass flow rate to …

Coreless Planar Transformer Using Low-Temperature Co-Fired Ceramics For Isolated Gate Driver Applications, Matthew W. Feurtado

Electrical Engineering Undergraduate Honors Theses

The aim of this thesis project is to design a signal isolation transformer for gate driver applications using coreless planar transformers (CPT) on a low-temperature co-fired ceramic (LTCC) substrate. To achieve this goal a modulator-demodulator circuit will be selected from several existing designs and an isolation transformer will be designed as a CPT to produce a high frequency high temperature signal isolation for gate driver applications in switching converters, audio drivers, and motor drives. Several designs for coreless planar transformers will be evaluated and tested, and the results will be compared to the theoretical performance obtained from SPICE models for …

A Study On The Micro Electro-Discharge Machining Of Aerospace Materials, Mychal-Drew Moses

Masters Theses & Specialist Projects

Electrical Discharge Machining (EDM) is a non-traditional machining process that uses hundreds of thousands of minute electrical sparks per second to machine any electrically conductive material, no matter the hardness or how delicate it is. EDM allows a much greater range of design possibilities, unconstrained from the traditional machining processes, in which material is removed mechanically by either rotating the cutting tool or the work piece. Shapes that were impossible to machine by any other method, such as deep, precision, square holes and slots with sharp inside corners, are readily produced. It provides accurate geometries in high- aspect ratio holes …

A Comparative Study On Micro Electro-Discharge Machining Of Titanium Alloy (Ti-6al-4v) And Shape Memory Alloy (Ni-Ti), Pegah Kakavand

Masters Theses & Specialist Projects

The purpose of this research was to investigate the surface modifications that take place during the machining of NiTi SMA and Ti-6Al-4V with micro-EDM. This was done by creating an array of blind holes and micro-patterns on both work-pieces. To analyze the machined surface and investigate the results, scanning electron microscope (SEM), energy dispersive X- ray spectroscopy (EDS) and X-ray diffraction (XRD) techniques were employed. In addition, the effects of various operating parameters on the machining performance was studied to identify the optimum parameters for micro-EDM of NiTi SMA and Ti-6Al-4V. Recently, aerospace and biomedical industries have placed a high …

Phased Array Beamsteering In Composite Laminates For Guided Wave Structural Health Monitoring, Peter Osterc

Doctoral Dissertations and Master's Theses

In this study a guided wave phased array beamsteering approach is applied to composite laminates. Current beamsteering algorithms derived for isotropic materials assume omnidirectional wave propagation. Due to inherent anisotropy in composites, guided wave propagation varies with direction and wavefronts no longer have perfect circular shapes.

By examining slowness, velocity and wave curves, as well as amplitude variation with direction for a given composite laminate, the wavefront from a single source can be described as a function of the angle of propagation and distance from origin. Using this approach, a more general delay and sum beamforming algorithm for composite laminates …

Non-Destructive Techniques For Classifying Aircraft Coating Degradation, Kody A. Wilson

Theses and Dissertations

In this research non-destructive techniques were examined as possible methods of determining aircraft coating degradation. Single Value Decomposition(SVD)-Linear Discriminant Analysis(LDA) algorithms were applied to measured spectra. When applied to infrared emittance spectra only 52% classification accuracy was achieved. When applied to Raman spectroscopy a higher classification accuracy of 70.4% is attained when using the same SVD-LDA algorithm. However the best performing measurement was using infrared reflectance classification accuracies were 100%, 99.83% and 94.4% when using the Bomem FTS, DRIFTS and Telops respectively for one of the sample sets. For DRIFTS data a more accurate fingerprint region was identified 865.6 - …

Methods Of Measuring Stress Relaxation In Composite Tape Springs, Justin T. Heppe

Theses and Dissertations

Composite tape springs present an opportunity to use stored energy for the deployment of space structures. Concern has risen over the dissipation of strain energy during storage due to viscoelasticity inherent in polymeric materials commonly used as the composite matrix. Tests to measure the internal behavior of a composite tape spring over time are conducted along with methods of analyzing and fitting the resulting data. The three constant strain configurations tested were compression force of the cross section, a restraining force of a longitudinal fold, and the change in shape of a folded section. While the shape changing test did …

Effect Of Prior Exposure At Elevated Temperatures On Tensile Properties And Stress-Strain Behavior Of Three Oxide/Oxide Ceramic Matrix Composites, Christopher J. Hull

Theses and Dissertations

Thermal stability of three oxide-oxide ceramic matrix composites was studied. The materials studied were Nextel^TM610/aluminosilicate (N610/AS), Nextel^TM720/aluminosilicate (N720/AS), and Nextel^TM720/Alumina (N720/A), commercially available oxide-oxide ceramic composites (COI Ceramics, San Diego, CA). The N610/AS composite consists of a porous aluminosilicate matrix reinforced with laminated woven alumina N610 fibers. The N720/AS and N720/A composites consist of a porous oxide matrix reinforced with laminated, woven mullite/alumina (Nextel^TM720) fibers. The matrix materials are aluminosilicate in N720/AS and alumina in N720/A. All three composites have no interface between the fibers and matrix, and rely on the porous …

Tension-Compression Fatigue Of An Oxide/Oxide Ceramic Matrix Composite At Elevated Temperature In Air And Steam Environments, Richard L. Lanser

Theses and Dissertations

Tension-compression fatigue behavior of an oxide-oxide ceramic matrix composite was investigated at 1200°C in air and steam. The composite is comprised of an alumina matrix reinforced with Nextel 720 fibers woven in an eight harness satin weave. The composite relies on a porous matrix for damage tolerance. Compression and tension tests to failure were conducted to characterize basic mechanical properties. Tension-compression fatigue tests were performed at 1 Hz frequency with a ratio of minimum to maximum stress of -1. Maximum stresses ranged from 60-120 MPa. Fatigue run-out (defined as 105 cycles) was achieved in air at 80 MPa and in …

Mechanical Testing Of Ultra-High Temperature Ceramics At 1500°C In Air -Development Of An Experimental Facility And Test Method, Sheena L. Winder

Theses and Dissertations

With a melting point in excess of 3000°C and a high density, ultra-high temperature ceramics (UHTCs) are a candidate material for hypersonic flight vehicles, atmospheric re-entry vehicles, and rocket propulsion systems. When ceramics are under consideration as a structural material, creep is an important design criterion and a life-limiting condition. However, the characterization of mechanical behavior at temperatures in excess of 1300°C has many challenges to overcome. Of utmost importance is the selection of materials for test fixtures. Materials selected must maintain their structural integrity, not cause chemical degradation of the test material, and not interfere with the acquisition of …

Effect Of Sustainable And Composite Materials On The Mechanical Behavior Of Sandwich Panels Under Edgewise Compressive Loading, Justin A. Tafoya

Master's Theses

Over the last three decades, the aerospace industry has gradually shifted from metals to composites in many different applications due to the lightweight properties of composite materials. Some benefits of composites include higher strength-to-weight ratio and corrosion resistance. At this point in time, the composite industry researchers are focusing on renewable and sustainable materials (bio-composites). By understanding the structural capabilities of bio-composites that have been used for centuries, new developments of sustainable materials will spark more interest throughout the industry. Bio-composites include fibers such as hemp, bamboo, flax, etc. The high demand for bio-composites in composite structures can also reduce …

Suborbital Spaceflight: A Student Team’S Plan To Send A Rocket To Space, Bryce Chanes, William Carpenter, Julio Benavides, Matthew Haslam, Brenda Haven

Aviation / Aeronautics / Aerospace International Research Conference

The Eagle Space Flight Team was created with the goal of becoming the first undergraduate team to design, build, and launch a rocket capable of suborbital spaceflight. In order to achieve this goal, the team will have to design a rocket capable of atmospheric flight at speeds over Mach 5 and launch it on one of the largest amateur rocket motors ever made. Over the next three years, the team will progress towards accomplishing this feat through a series of incremental test flights. Before the space flight, the team will build three sub-scale rockets designed to reach altitudes of 30,000’, …

A Multi-Scale Based Model For Composite Materials With Embedded Pzt Filaments For Energy Harvesting, A.E. El-Etriby, M.E. Abdel-Meguid, K.M. Shalan, Tarek Hatem, Yehia Bahei-El-Din

Centre for Advanced Materials

Ambient vibrations are major source of wasted energy, exploiting properly such vibration can be converted to valuable energy and harvested to power up devices, i.e. electronic devices. Accordingly, energy harvesting using smart structures with active piezoelectric ceramics has gained wide interest over the past few years as a method for converting such wasted energy. This paper provides numerical and experimental analysis of piezoelectric fiber based composites for energy harvesting applications proposing a multi-scale modeling approach coupled with experimental verification. The multi-scale approach suggested predicting the behavior of piezoelectric fiber-based composites use micromechanical model based on Transformation Field Analysis (TFA) to …

Shape Memory Behavior Of Single Crystal And Polycrystalline Ni-Rich Nitihf High Temperature Shape Memory Alloys, Sayed M. Saghaian

Theses and Dissertations--Mechanical and Aerospace Engineering

NiTiHf shape memory alloys have been receiving considerable attention for high temperature and high strength applications since they could have transformation temperatures above 100 °C, shape memory effect under high stress (above 500 MPa) and superelasticity at high temperatures. Moreover, their shape memory properties can be tailored by microstructural engineering. However, NiTiHf alloys have some drawbacks such as low ductility and high work hardening in stress induced martensite transformation region. In order to overcome these limitations, studies have been focused on microstructural engineering by aging, alloying and processing.

Shape memory properties and microstructure of four Ni-rich NiTiHf alloys (Ni50.3Ti29.7Hf20, Ni50.7Ti29.3Hf20, …

Design Of The Structural And Propulsion Systems For The 2015 University Of Akron Rocket Team, Kyle W. Dehoff, Nicholas J. Hrusch

Williams Honors College, Honors Research Projects

No abstract provided.

Damage Characteristics In 3d Stitched Composites With Various Stitch Parameters Under In-Plane Tension, Arief Yudhanto, Gilles Lubineau, Isaac Aguilar Ventura, Naoyuki Watanabe, Yutaka Iwahori, Hikaru Hoshi

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Three-dimensional (3D) reinforcement by stitching is effective in improving the impact resistance of composites. Stitching, however, adversely affects the composite's in-plane mechanical responses, and alters its damage mechanisms due to stitch-induced irregularities. We experimentally investigate the effect of two important stitch parameters, stitch density and thread diameter, on the damage characteristics of 3D stitched multidirectional composites under in-plane tension using X-ray radiography, X-ray micro-computed tomography and digital image correlation (DIC). Our study shows that composites stitched with thicker thread exhibit improved tensile strength due to effective hindrance of edge-delamination. We also found that stitch thread affects damage behaviors. A higher …

Modal Characterization And Structural Dynamic Response Of A Crane Fly Forewing, Jose E. Rubio

LSU New Orleans Theses and Dissertations

This study describes a method for conducting the structural dynamic analysis of a crane fly (family Tipulidae) forewing under different airflow conditions. Wing geometry is captured via micro-computed tomography scanning. A finite element model of the forewing is developed from the reconstructed model of the scan. The finite element model is validated by comparing the natural frequencies of an elliptical membrane with similar dimensions of the crane fly forewing to its analytical solution. Furthermore, a simulation of the fluid-structure interaction of the forewing under different airflows is performed by coupling the finite element model of the wing with a …

Heat Transfer Enhancement And Applications Of Femtosecond Laser Processed Metallic Surfaces, Corey M. Kruse

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

In the present work, functionalized 304 stainless steel metallic surfaces were created with the use of a Femtosecond Laser Surface Processing (FLSP) technique. The laser processing technique produces self-organized micro/nanostructures on the surface. The heat transfer performance of various FLSP functionalized surfaces were characterized through pool boiling and Leidenfrost experiments. Enhancement in both the nucleate and film boiling heat transfer were observed through an increase of the critical heat flux and heat transfer coefficient as well as shifts in the Leidenfrost temperature respectively. For both experiments, a polished reference sample was used as a baseline line to compare against the …

Development, Analysis, And Comparison Of Electromechanical Properties And Electrode Morphology Of Ionic Polymer Metal Composites, Balaji Sivasubramanian

Doctoral Dissertations and Master's Theses

With smart materials and adaptive structures being nudged into mainstream technology progressively, the smart composites are donning a predominant role as indispensable structures. Among these, the Ionic Polymer Metal Composites (IPMC), with their large bending deformation and relaxation characteristics at very low voltages are attractive as transducers in many areas of application. The actuation and sensing properties of IPMC have been sought after for various engineering functions. The paper focuses on manufacturing various types of IPMC. Combining the ionic polymer with platinum electrodes, gold sputter coated electrodes and multi-walled carbon nanotube Bucky paper electrodes to create enhanced IPMCs, comparative analysis …

Achieving Global Range In Future Subsonic And Supersonic Airplanes, Nihad E. Daidzic Ph.D., Sc.D.

International Journal of Aviation, Aeronautics, and Aerospace

No commercial airplane in service today is able to fly half great-circle distances over the globe and achieve the non-stop or the global range to any antipodal location on Earth. A subsonic jetliner has the optimum cruising speed at Mach numbers approaching the drag divergence Mach number while still preserving relatively high aerodynamic efficiency. Various fuel-flow laws were used to investigate the cruise performance of subsonic and supersonic aircraft. The effect of wind and aircraft weight and how it affects the optimal cruising airspeed was investigated. Of all different operational cruising techniques, the cruise-climb at high Mach numbers is the …

To Study The Effect Of Catalyst On The Physical Parameters Of Carbon Spheres, Tejas Shailesh Mehta

Doctoral Dissertations and Master's Theses

The discovery of fullerenes has opened up modern studies in carbon materials. Carbon nanoparticles have a large surface area and demonstrate good conductivity. Their unique properties has gained attention in many areas such as water filtration, hydrogen storage and battery electrodes. In this research, carbon spheres with high specific area and uniformity were grown using the Chemical Vapor Deposition (CVD) process with silicon substrates, ethylene (C2H4) as a carbon precursor and argon as the inert gas. We observe that the morphology of carbon spheres largely depend on the experimental conditions, including CVD time duration, temperature, catalyst and flow of gases. …

Investigation Of Conjugate Heat Transfer In Fluid-Structure Interaction Modeling Using Openfoam, Andrew Brown

Aerospace Engineering

No abstract provided.

Improving And Expanding The Capabilities Of The Poly-Picosatellite Orbital Deployer, David Pignatelli

Master's Theses

The Poly-Picosatellite Orbital Deployer (P-POD) has undergone a series of revisions over the years. The latest revision, described in this Master’s Thesis, incorporates new capabilities like EMI shielding, an inert gas purge system, and an electrical interface to the CubeSats after they are integrated into the P-POD. Additionally, some mass reduction modifications are made to the P-POD, while its overall strength is increased. The P-POD inert gas purge system successfully flew, on a previous revision P-POD. The P-POD components are analyzed to a set of dynamic loads for qualification, and successfully undergoes random vibration qualification testing. The P-POD encounters some …

Effects Of Low Velocity Impact On The Flexural Strength Of Composite Sandwich Structures, Jeffrey Scott Carter

Master's Theses

The use of composite sandwich structures is rapidly increasing in the aerospace industry because of their increased strength-to-weight and stiffness-to-weight characteristics. The effects of low velocity impacts on these structures, however, are the main weakness that hinders further use of them in the industry because the damages from these loadings can often be catastrophic. Impact behavior of composite materials in general is a crucial consideration for a designer but can be difficult to describe theoretically. Because of this, experimental analysis is typically used to attempt to describe the behavior of composite sandwiches under impact loads. Experimental testing can still be …

A Comparison Of Afghanistan, Yuma, Az, And Manufactured Sands Melted On Eb-Pvd Thermal Barrier Coatings, Nathaniel P. Opie

Theses and Dissertations

Sand ingestion into military aircraft turbine engines from desert environments have tested the performance and life of the engine. In particular, turbine section blades and nozzles are coated with a molten glass when the sand is heated to melting temperatures. This molten glass attacks protective coatings on the surface of these parts. Further research is needed to understand the sands behavior on thermal barrier coatings (TBC) when heated to melting temperatures. Also, further research is needed with manufactured sand used in current engine testing to understand the sand ingestion discrepancies between test engines and operational engines. In this study natural …

Dynamic Analysis Of Granular Battery Assembly, Rohan Dudaney, Waterloo Tsutsui, Weinong Chen

The Summer Undergraduate Research Fellowship (SURF) Symposium

Collisions and impacts are an inevitable reality when it comes to commercial cars and vehicles, but as batteries become more prevalent it is vital to understand how they react dynamically and as a system to better protect both the passengers and toxic chemicals inside of the batteries. One potential solution is to surround these batteries with non-vital tubes that can be sacrificed and help protect the batteries. This study is done to understand the structure of batteries and to test how an assembly of sacrificing cells and batteries reacts in an impact situation to see if there is significant energy …

Fiber Length And Orientation In Long Carbon Fiber Thermoplastic Composites, Imad Hanhan, Connor Sullivan, Bhisham Sharma, Michael Sangid

The Summer Undergraduate Research Fellowship (SURF) Symposium

Carbon fiber composites have become popular in aerospace applications because of their lightweight yet strong material properties. The injection molding process can be used to produce discontinuous fiber composites using less time and resources than traditional methods, thereby broadening carbon fiber composites’ applications in different industries. Utilization of longer fibers offers more load carrying capability and superior strength properties for injected molded composites. Since the fiber length and the orientation distribution in Long Fiber Thermoplastics (LFTs) directly affects LFT composites’ material properties, there is a need to study the microstructure of LFTs and characterize fiber length and orientation distributions. Therefore, …

Simulation Of Bio-Inspired Porous Battery Electrodes, Raju Gupta, R. Edwin Garcia, Rui Tu

The Summer Undergraduate Research Fellowship (SURF) Symposium

Advancement of technology has led to the increase in use of electronic devices. However, longer life of the rechargeable battery used in electronic devices is one of the biggest issue and demand in the world of electronic devices at present. Battery's performance is affected by the orientation, arrangement, shape and size, and porosity of the materials out of which battery electrodes are made. The goal of this project is to develop a set of numerical libraries that allow developing material micro structures that will allow increasing the performance of rechargeable batteries. We focused on the development of an algorithm that …

Dynamic Response Of Textile Material Under Transverse Impact, Yuchen Zheng, Matthew C. Hudspeth, Weinong W. Chen

The Summer Undergraduate Research Fellowship (SURF) Symposium

Textile materials, such as Dyneema and Kevlar, are the major raw materials for state of the art military or personal security armor vests. However, in impact experiments, actual observed penetration speed is much lower than theoretically predicted penetration speed. Each armor vest is composed of high performance yarns which are woven together to form fabrics, which when stacked together form a vest. Understanding penetration behavior of yarns is essential to evaluate the performance of fabric, which will be useful for the design of better vests. The project is composed of three parts: static experiments, dynamic yarn experiments and dynamic fabric …