Aerospace Engineering Commons^™

Energy Dissipation In A Sand Damper Under Cyclic Loading, Ehab Sabi

Civil and Environmental Engineering Theses and Dissertations

Various seismic and wind engineering designs and retrofit strategies have been in development to meet structures' proper and safe operation during earthquake and wind excitation. One such method is the addition of fluid and particle dampers, such as sand dampers, in an effort to reduce excessive and dangerous displacements of structures. The present study implements the discrete element method (DEM) to assess the performance of a pressurized sand damper (PSD) and characterize the dissipated energy under cyclic loading. The idea of a PSD is to exploit the increase in shearing resistance of sand under external pressure and the associated ability …

Additively Manufactured Lenses For Modulating Guided Waves In Laminated Composites, Hajar Righi

Theses and Dissertations

Composite materials have increasingly been used as an alternative to metals and other isotropic materials for primary structural components in aerospace industries. Unlike traditional isotropic materials, composite materials are known to have complex internal microstructures. Therefore, it is essential to develop methods for the inspection, evaluation, and monitoring of composite materials. Ultrasonic-guided waves and, more precisely, Lamb waves have proven to be an efficient and accurate technique for the non-destructive testing. Since guided waves are dispersive and multimodal, it is important to develop a practical method to manipulate Lamb waves to achieve better structural health monitoring and non-destructive inspection results. …

Metal Organic Framework Modifications Of Structural Fibers, Marwan Al-Haik

Publications

A reinforced carbon composite can include a carbon sub­strate and a metal organic framework bonded to the carbon substrate. For example, a reinforced carbon composite can include a first layer, a second layer, and a resin adhered to the first layer and the second layer. The first layer can include a carbon substrate and a metal organic framework bonded to the carbon substrate. The second layer can include a carbon substrate and a metal organic framework bonded to the carbon substrate.

Carbon Fibers From Bio-Based Precursors Derived From Renewable Sources, Sagar Kanhere

All Dissertations

Carbon fibers have the highest strength and modulus among all known fibers and are used as reinforcements in high-performance composites [1]. Carbon fibers also have a very low density relative to metals. Therefore, carbon fibers possess ultrahigh specific strength and modulus, which make them desirable for high-performance light-weight composites. A vast majority of commercial carbon fibers are produced from PAN precursors that are expensive, which limits the use of PAN-derived carbon fibers to aerospace applications (e.g., airplanes). However, for costsensitive applications, there is a need for low-cost, moderate performance carbon fibers. Lignin is a low-cost by-product of pulping and biorefining …

Natural 2d Layered Mineral Cannizzarite With Anisotropic Optical Responses, Arindam Dasgupta, Xiaodong Yang, Jie Gao

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Cannizzarite is a naturally occurring mineral formed by van der Waals (vdW) stacking of alternating layers of PbS-like and Bi2S3-like two-dimensional (2D) materials. Although the PbS-type and Bi2S3-type 2D material layers are structurally isotropic individually, the forced commensuration between these two types of layers while forming the heterostructure of cannizzarite induces strong structural anisotropy. Here we demonstrate the mechanical exfoliation of natural cannizzarite mineral to obtain thin vdW heterostructures of PbS-type and Bi2S3-type atomic layers. The structural anisotropy induced anisotropic optical properties of thin cannizzarite flakes are explored through angle-resolved polarized Raman scattering, linear dichroism, and polarization-dependent anisotropic third-harmonic generation. …

Effects Of Atomic Oxygen On Outgassing Of Silicone Materials, Samuel Westrick

Master's Theses

An important consideration for spacecraft material selection is the space environment that the spacecraft will be operating in. Two features of the space environment that drive material selection are material outgassing and the presence of atomic oxygen in low Earth orbit (LEO). Materials that are considered for use in space are tested to be able to understand how they’ll outgas on orbit and how they’ll respond to interactions with atomic oxygen. However, testing to understand how atomic oxygen interaction with a material will affect how the material will outgas is rare and not standardized. This thesis used a vacuum chamber …

Fracture Strength Of Multi-Component Ultra-High Temperature Carbides, Gia Garino

2022 MME Undergraduate Research Symposium

Ultra-high temperature ceramics (UHTCs) have emerged as a promising material for next generation re-entry hypersonic vehicles due to high melting point (>3000 °C), and high mechanical properties and oxidation resistance. Yet none of the unary UHTCs can satisfy the whole gamut of demanding requirements for aerospace applications. Recently, the single-phase solid-solution formation in a multi-component ultra-high temperature ceramic (MC-UHTC) materials have gained interest due to their superior thermo-mechanical properties compared to conventional UHTCs. Herein, a systematic approach was used to fabricate binary (Ta, Nb)C, ternary (Ta, Nb, Hf)C, and quaternary (Ta, Nb, Hf, Ti)C UHTCs by gradual addition of …

Manufacturability And Analysis Of Topologically Optimized Continuous Fiber Reinforced Composites, Jesus A. Ferrand

Doctoral Dissertations and Master's Theses

Researchers are unlocking the potential of Continuous Fiber Reinforced Composites for producing components with greater strength-to-weight ratios than state of the art metal alloys and unidirectional composites. The key is the emerging technology of topology optimization and advances in additive manufacturing. Topology optimization can fine tune component geometry and fiber placement all while satisfying stress constraints. However, the technology cannot yet robustly guarantee manufacturability. For this reason, substantial post-processing of an optimized design consisting of manual fiber replacement and subsequent Finite Element Analysis (FEA) is still required.

To automate this post-processing in two dimensions, two (2) algorithms were developed. The …

Passive, Self-Healable, Dielectric Elastomers For Structural Health Monitoring, Nicholas Smith

Doctoral Dissertations and Master's Theses

NASA maintains the ability to track a large majority of objects in Earth’s orbit, however lack the ability to track objects smaller than five centimeters in diameter. These untrackable objects represent a significant danger to inflatable structures. This work seeks to synthesize and fabricate a self-healable, passive, dielectric elastomer impact sensor for structural health monitoring on inflatable space structures subject to impact by micrometeoroids and orbital debris. In a setting in which impact repairs can be extremely costly, the implementation of such a technology would not only alert personnel of such an event but would also serve to decrease the …

Development Of A Trailing Edge Flap Using A Compliant Mechanism, Matthew Maybee

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Development Of New Space Systems Architecture In Sysml Using Model-Based Pattern Language, Bhushan R. Lohar

<strong> Theses and Dissertations </strong>

This manuscript presents an approach to the application of the Model-Based Systems Engineering (MBSE) and Model-Based Systems Architecting (MBSA) principles to develop a Model-Based Pattern Language (MBPL). It takes considerable time for systems engineers and mission architects to develop a new system from scratch, particularly new space-based systems derived from the existing space system architectures. The use of a pattern language which is a holistic view of reusable logical model artifacts, can improve the process.

The main benefit of the pattern language is to reduce the time and validation required to generate a new space-based system architecture; this approach will …

Synthetic Gecko Inspired Dry Adhesive Through Two- Photon Polymerization For Space Applications, Zefu Ren

Doctoral Dissertations and Master's Theses

This work aims to develop an advanced and cost-effective fabrication process to produce a simplified gecko-inspired microstructure with two-photon polymerization and polymer molding, aimed to improve the adhesive properties of microstructures. Such adhesive microstructures can be implemented for multi-purpose adhesive grasping devices, which have recently gained significant interest in the space exploration sector. Previous gecko-inspired microstructures were reviewed, and the new gecko-inspired microstructures have been developed with the adaptation of additive manufacturing methods for facile fabrication. The examined microstructures in this thesis were the tilted mushroom-shaped and wedge-shaped designs, which could both maximize adhesion by shearing the micropillars toward the …

Uv Space Imager Enclosure Coating, David Silva Cortez, Victor Alexander Rempel Dekhtyar, Maria L. Muñoz

Mechanical Engineering

The goal of this project is to reduce the amount of stray light entering an ultraviolet (UV) imager through absorption. This report outlines the use of ZnO nanoparticles mixed in an epoxy matrix for use in a CubeSat enclosure. Through testing, our team verified that the ZnO and epoxy coating experienced a peak absorption between 360-370 nm. The epoxy mixture with the .75% by weight ZnO nanoparticles absorbed up to 99.9 % of UV light at its peak. The effect on material properties, such as Young’s modulus and ultimate tensile strength, was also tested. Tensile tests demonstrated that adding ZnO …

Structural Loads And Preliminary Structural Design For A World Speed Record-Breaking Turbo-Prop Racing Airplane, Matthew G. Slymen

Master's Theses

The Cal Poly SLO Turbo-Prop Racer project aims to design a world speed record-breaking aircraft, capable of flying more than 550 miles per hour on a 3-kilometer closed course. To further this endeavor, this thesis presents the calculations of load distributions across the aircraft’s wing and tail and preliminary structural estimates of primary structural components for verification of the loads calculations and for use in a future finite element model. The aircraft’s fundamental design characteristics effect on the structure of the aircraft, namely the unique Y-tail design, are first examined. Then, loads are calculated in accordance with the regulation dictated …

Structural Sizing Of Post-Buckled Thermally Stressed Stiffened Panels, Walid Arsalane

Theses and Dissertations

Design of thermoelastic structures can be highly counterintuitive due to design-dependent loading and impact of geometric nonlinearity on the structural response. Thermal loading generates in-plane stresses in a restrained panel, but the presence of geometric nonlinearity creates an extension-bending coupling that results in considerable transverse displacement and variation in stiffness characteristics, and these affects are enhanced in post-bucking regimes. Herein a methodology for structural sizing of thermally stressed post-buckled stiffened panels is proposed and applied for optimization of the blade and hat stiffeners using a gradient-based optimizer. The stiffened panels are subjected to uniform thermal loading and optimized for minimum …

Novel Thermal Coating For High-Speed Airplanes, Abinash Satapathy, Lakshay Battu, Liam Watson, Nazanin Rajabi

Symposium of Student Scholars

In comparison to various other materials, Carbon Fiber, specifically Carbon Fiber Reinforced Polymers (CFRP), is pre-eminent amongst other materials for use on aeronautical systems. Due to its high specific strength (strength-to-weight ratio), CFRP is prominent for carrying heavy loads while maintaining a lightweight build. However, when influenced by heat resulting from air resistance, CFRP is known to undergo serious degradation that would significantly decrease the effectiveness of the polymers. To prevent this degradation and maintain the strength of the CFRP, thermal protective layers (TPLs) are designed to shield the CFRP from heat exposure. This research is focused on the examination …

The Effect Of Pre-Thermal And -Load Conditions On In-718 High Temperature Fatigue Life, Paulina De La Torre, Alberto Mello

Publications

Ni-based superalloys are largely used in the aerospace industry as critical components for turbine engines due to their excellent mechanical properties and fatigue resistance at high temperatures. A hypothesis to explain this atypical characteristic among metals is the presence of a cross-slip mechanism. Previous work on the role of thermal activation on cubic slip has shown strain accommodation in two sets of slip planes, which resembled the activation of {100} cubic slip systems along of the octahedral slip planes {111} in Ni-based superalloys under high strain and temperature, exhibiting a more homogeneous strain distribution and less strain localization. Following those …

Influence Of Cold Expansion And Aggressive Environment On Crack Growth In Aa2024-T3, Ken Shishino, Christopher Leirer, Alberto Mello

Publications

This research aims to establish the effect of hole cold expansion on fatigue life of pre-cracked material under aggressive environment. A relationship between crack propagation and secondary crack initiation was established for AA2024-T3 cold worked holes subjected to cyclic loads to determine the impact on fatigue life of joints in presence of saline solution. Galvanic corrosion of a steel fastener/aluminum plate assembly was investigated assuming the presence of cracks in the aluminum plates, whose growth will be monitored in-situ with a digital microscope throughout the fatigue process. The cold expansion treatment improved the fatigue life fourfold under a corrosive environment, …

Investigation Of Additively Manufactured Molybdenum-Tungsten-Rhenium Alloys, Randolph T. Abaya

Theses and Dissertations

The process of creating metal components through additive manufacturing is changing the way different industries can avoid the shortcomings of traditional metal production. Metals such as tungsten, molybdenum, and rhenium have many advantages for different applications, especially when alloyed together. In this study, an additively manufactured alloy containing 70% molybdenum, 25% tungsten, and 5% rhenium (70Mo-25W-5Re) is tested for its strength, ductility, hardness, and porosity. The 70Mo-25W-5Re alloy is printed through Laser Powder Bed Fusion (LPBF) under different conditions such as printing speed and printing atmosphere. Additionally, the effects of post printing heat treatment are conducted to understand the advantages …

Thermal Relaxation Of Shot Peen Induced Residual Stresses In A Nickel-Base Superalloy, Bryce E. Van Velson

Theses and Dissertations

Shot peening induces compressive residual stresses in components that positively influence fatigue life. Thermal and mechanical loading causes those residual stresses to relax. The hole drilling method and xray diffraction is used to measure the thermal relaxation of residual stresses in the nickel-base superalloy ME3.

Aeroelastic Analysis Of Small-Scale Aircraft, Kent Roberts

Master's Theses

The structural design of flight vehicles is a balancing act between maximizing loading capability while minimizing weight. An engineer must consider not only the classical static structural yielding failure of a vehicle, but a variety of ways in which structural deformations can in turn, affect the loading conditions driving those deformations. Lift redistribution, divergence, and flutter are exactly such dynamic aeroelastic phenomena that must be properly characterized during the design of a vehicle; to do otherwise is to risk catastrophe. Relevant within the university context is the design of small-scale aircraft for student projects and of particular consideration, the DBF …

Effects Of A Nitrogen And Hydrogen Build Atmosphere On The Properties Of Additively Manufactured Tungsten, Dana C. Madsen

Theses and Dissertations

Additively manufactured tungsten was printed in pure nitrogen, nitrogen-2.5% hydrogen, and nitrogen-5% hydrogen atmospheres as part of a 2^3 full factorial designed experiment and subjected to room temperature and high-temperature three-point-bend testing, chemical analysis, hardness testing, and microstructural imaging techniques. The pure nitrogen specimens exhibited the highest strength and ductility at both high temperature and room temperature. Chemical analysis showed a 2-8x reduction in compositional oxygen relative to unprocessed powder. Hardness values for all samples was between 306.8 and 361.5 HV1. It is proposed that adding hydrogen into the build atmosphere reduced the available energy density for tungsten melting by …

Jcati Carbon Fiber Recycler: Oven Enclosure, Margarita Romero

All Undergraduate Projects

Central Washington University partners with Boeing and is funded by the Joint Center of Aerospace Technology Innovation (JCATI) to develop a mechanism that takes carbon fiber wing trimmings from Boeing that are resin coated and recycles carbon fiber. This is done by crushing the wing trimmings and then putting it into a 500°C oven to melt off the resin. This project focuses on the enclosure for the oven and making sure precautions are met such as having the outside surface be less than 45c through heat transfer analysis, argon fills enclosure in 13 minutes through fluid dynamics analysis, and 99% …

Carbon Fiber Recycling: Delamination System, Aaron Eastman

All Undergraduate Projects

The production of composite wings at Boeing causes carbon fiber waste and CWU Mechanical Engineering Technology students have been tasked in designing a carbon fiber recycling system. This project was brought forth and funded by the Joint Center for Aerospace Technology Innovation (JCATI). There are three subsystems that make up the carbon fiber recycling system, the delamination system, shredding system, and the oven. The purpose of this project was to increase the efficiency and effectiveness of the delamination system of the carbon fiber recycling system. The old system reached approximately 30-40 percent delamination with one pass through the system, and …

Jcati Carbon Fiber Shredder 2022, Parker Sudderth

All Undergraduate Projects

This project is a potential solution to keep the carbon fiber waste from airplane manufacturing to a minimum, sponsored by the Joint Center for Aerospace Technology Innovation (JCATI). The design and assembly will be scalable for future industry application. The overall design of the whole carbon fiber recycler consists of a crusher, shredder, and oven. This report is on the caron fiber shredder module. The shredder is tasked with being able to shred the delaminated carbon fiber scrap that directly comes from the crusher. The operation must produce shreds in the proper size to be gathered and delivered to the …

Model-Based Systems Engineering For A Small-Lift Launch Facility, Walter Mcgee Taraila, Sharanabasaweshwara Asundi

Mechanical & Aerospace Engineering Faculty Publications

A study of model‐based systems engineering (MBSE) applied to a small‐lift launch facility is presented. The research uses Systems Modeling Language (SysML) products and functional diagrams to document the ground systems on a launch pad servicing a small class payload (0–2 tons). With the projected growth in launch cadence of small‐lift rockets in the coming decade, there is a need to design increasingly complex launch systems with greater efficiency. The potential improvements in project communication, quality, and productivity are explored by developing a model following the ISO/IEC 15288 technical process framework and the International Council on Systems Engineering (INCOSE) Object‐Oriented …

Microscale Transverse Compression Modeling: A Comparative Study Of The Analytical Mac/Gmc Methods To Experimental Results, Emily Zeitunian

Dissertations, Master's Theses and Master's Reports

Composite materials require a multi-scale approach to fully understand its behavior. At the micro level, material behavior analysis is conducted most often using numerical or analytical approaches. These models, however, require validation from experimental data to ensure material predictions are accurate. This study compares a semi-analytical micromechanical analysis tool, MAC/GMC, to experimental results of in-situ microscale transverse compression testing conducted at AFRL facilities. Effective properties, stress-strain curves, stress and strain fields, and damage predictions are compared with experimental outputs. Both generalized method of cells (GMC) and high-fidelity generalized method of cells (HFGMC) theories implemented within MAC/GMC show results that agree …

Design, Development, And Testing Of Near-Optimal Satellite Attitude Control Strategies, Giovanni Lavezzi

Electronic Theses and Dissertations

Advances in space technology and interest toward remote sensing mission have grown in the recent years, requiring the attitude control subsystems of observation satellites to increase their performances in terms of pointing accuracy and on-board implementability. Moreover, an increased interest in small satellite missions and the recent technological developments related to the CubeSats standard have drastically reduced the cost of producing and flying a satellite mission. In this context, the proposed research aims to improve the state of the art for satellite attitude control methodologies by proposing a near-optimal attitude control strategy, simulated in a high-fidelity environment. Two strategies are …

Autonomous Payload Design With Systems Engineering, Michael Downs, Christopher James Liebhart 2nd

Williams Honors College, Honors Research Projects

The design will be an autonomous payload consisting of auto deployment of a drone running an autonomous mission of mapping the terrain around a grounded rocket. The project is part of the Akronauts payload project for the 2022 Spaceport competition. It will include the development of a ground station for monitoring and controlling the drone and the transfer of live data to the station and a computer on board the rocket. The project will aim to use system engineering techniques to accomplish this in the hope of providing documentation and thus insight into the best way to develop a multi-disciplinary …

Digital Image Correlation System Design, Verification And Analysis, Tyler Kraft, Matthew J. Riczo, Andrew Chong

Williams Honors College, Honors Research Projects

Two dimensional digital image correlation provides an accurate and effective way to capture strain data on test sections with unusual or oblique geometries. The system requires a camera to record video footage, alignment fixtures and software to convert the footage into strain values. The system works by capturing the video footage of a specific portion of the specimen and comparing the movement of selected pixels. This is all done in the software GOM Correlate and Tracker. This test document outlines the setup, procedure, and validation steps to fulfill this goal. The setup involves a camera, tripod, blue lighting, and laser …