Structures and Materials Commons^™

Laser Shock Peening Pressure Impulse Determination Via Empirical Data-Matching With Optimization Software, Colin C. Engebretsen

Theses and Dissertations

Laser shock peening (LSP) is a form of work hardening by means of laser induced pressure impulse. LSP imparts compressive residual stresses which can improve fatigue life of metallic alloys for structural use. The finite element modeling (FEM) of LSP is typically done by applying an assumed pressure impulse, as useful experimental measurement of this pressure impulse has not been adequately accomplished. This shortfall in the field is a current limitation to the accuracy of FE modeling, and was addressed in the current work. A novel method was tested to determine the pressure impulse shape in time and space by …

Carbon Fiber Composite Recycling, Wolfe Dennis

All Undergraduate Projects

During construction of Boeing’s aircrafts, carbon fiber reinforced composites are used as the primary material for the wings of the aircraft. Excess material during the manufacturing process is trimmed and discarded as waste. Although there is no viable process thus far, these trimmings have the potential to be recycled and reclaimed to be used in various other manufactured products. The trimmings of carbon fiber composite are approximately 10-12 layers of material bonded together. This project focuses on delaminating the trimmings into individual layers so that the carbon can be pyrolyzed from the bonding resin. In order to separate the layers …

Design Of Banner Tow Mechanism For Bush Plane, Kyle Ciarrone, Ivan Martin, Rishabh Gadi, Tyler Brandt

Williams Honors College, Honors Research Projects

The 2019-2020 AIAA DBF objective was to design, build, and test a banner-towing bush plane that carries wooden passengers and luggage. Senior members on the team undertook the creation of the banner tow mechanism subsystem as their senior design project on behalf of the design team due to the challenge of its mechanical design and the aerodynamic considerations regarding its placement and enclosure aboard the aircraft. The competition as well as access to campus resources were canceled due to COVID-19, so full testing and integration of the mechanism was not achieved. However, the engineering design process was experienced from the …

Evaluating The Effectiveness Of Aerospace Materials, Vehicle Shape And Astronaut Position At Lowering The Whole Body Effective Dose Equivalent In Deep Space, Daniel K. Bond

Theses and Dissertations

As future crewed, deep space missions are being planned, it is important to assess how spacecraft design can be used to minimize radiation exposure. Collectively with shielding material, vehicle shape and astronaut position must be used to protect astronauts from the two primary sources of space radiation: Galactic Cosmic Rays (GCR) and Solar Particle Events (SPE). GCRs, which are composed of low intensity, highly energetic, and fully ionized stable and meta-stable isotopes, are considered a chronic source of radiation risk to the astronauts. SPEs, which originate from solar coronal mass ejections, are composed mostly of high intensity protons that can …

Characterization Of Directed Energy Deposition Additively Manufactured Grcop-42 Alloy, Scott Landes

Electronic Theses and Dissertations

GRCop is an alloy family constructed of copper, chromium, and niobium and was developed by NASA for high heat flux applications. The first of its kind, GRCop-84, was specifically designed for the environments seen by channel cooled main combustion chamber liners. To further increase thermal conductivity while maintaining material strength characteristics, the percentage of alloying elements were cut in half and GRCop- 42 was developed. In recent years, NASA has successfully additively manufactured GRCop with comparable material characteristics to wrought GRCop using a Laser Powder Bed Fusion (L-PBF) process. Benefits of this process include fabrication of intricate cooling channels as …

Influence Of Size Effects On Surface Generation During Finish Machining And Surface Integrity In Ti-6al-4v, Ian S. Brown

Theses and Dissertations--Mechanical and Aerospace Engineering

Finish machining is an essential manufacturing process that is used to enhance the mechanical characteristics of critical components. The deformation that occurs at the tool and workpiece interface in finish machining significantly affects a host of component properties, commonly referred to as “surface integrity” properties. Surface roughness is a machining deformation-affected characteristic that is of high relevance in contemporary manufacturing. However, over recent decades it has been made clear that the material properties of the deformed surface layers are relevant to component performance as well. Predicting the overall surface quality of a machined component is of great relevance to the …

Carbon Oxidation At The Atomic Level: A Computational Study On Oxidative Graphene Etching And Pitting Of Graphitic Carbon Surfaces, Simon Schmitt

Theses and Dissertations--Mechanical and Aerospace Engineering

In order to understand the oxidation of solid carbon materials by oxygen-containing gases, carbon oxidation has to be studied on the atomic level where the surface reactions occur. Graphene and graphite are etched by oxygen to form characteristic pits that are scattered across the material surface, and pitting in turn leads to microstructural changes that determine the macroscopic oxidation behavior. While this is a well-documented phenomenon, it is heretofore poorly understood due to the notorious difficulty of experiments and a lack of comprehensive computational studies. The main objective of the present work is the development of a computational framework from …

Multiscale Modeling Of Carbon Fibers/Graphene Nanoplatelets/Epoxy Hybrid Composites For Aerospace Applications, Hashim Al Mahmud

Dissertations, Master's Theses and Master's Reports

Significant research effort has been dedicated for decades to improve the mechanical properties of aerospace polymer-based composite materials. Lightweight epoxy-based composite materials have increasingly replaced the comparatively heavy and expensive metal alloys used in aeronautical and aerospace structural components. In particular, carbon fibers (CF)/graphene nanoplatelets (GNP)/epoxy hybrid composites can be used for this purpose owing to their high specific stiffness and strength. Therefore, this work has been completed to design, predict, and optimize the effective mechanical properties of CF/GNP/epoxy composite materials at different length scales using a multiscale modeling approach. The work-flow of modeling involves a first step of using …

Redesign And Analysis For Landing Gear Components, Daniel Clarke

Williams Honors College, Honors Research Projects

A project for Collins Aerospace, the company I co-op at, where I will redesign several components of a landing gear for a military program. Any structural/stress analysis will also be performed. The goal is to reduce weight while maintaining strength and structural integrity.

Rocket Motor Nozzle, Corey Hillegass

Williams Honors College, Honors Research Projects

For this honors research and senior design project, the authors will research, analyze, and manufacture a rocket motor nozzle for the Akronauts rocket design team. This research and design project will improve how the rocket design team will decide and manufacture nozzles going forward. The impact of this improvement allows the rocket design team to take steps toward being self-sustaining by manufacturing student designed parts as opposed to commercially bought parts. This will not only be successful in increasing student impact on future designs, but also provides a technical challenge for the authors and will present as an impressive feat …

Experimental Evaluation Of Strength Degradation Temperature For Carbon Epoxy Filament Wound Composite, Jai Krishna Mishra, Surya Prakash Rao Ch Dr, Subhash Chandra Bose P Dr, Kishore Nath N Dr, Rama Rao Golla Mr

International Journal of Aviation, Aeronautics, and Aerospace

Polymeric composites have been widely used in various structural and thermal aerospace applications. Polymeric composites having high strength and high modulus reinforcement are ideally suited for lot of critical aerospace applications as structure is designed with high specific strength and high specific modulus. In case of launch vehicles/ missile one such application is design and manufacturing of solid rocket motor casing with polymeric composites as it give high performance and reduces inert weight of propulsion system. The high specific strength and high specific modulus of composite materials makes it ideal choice for designing the composite rocket motor case (CRMC). These …

Open-Ended Capstone Project: Designing And Manufacturing Of A Low-Cost Carbon Fiber Reinforced Composite Suborbital Rocket Payload Housing Using A 3d Printed Core, Garam Kim, Sergey Dubikovsky, Peng Hao Wang, Ronald Sterkenburg

International Journal of Aviation, Aeronautics, and Aerospace

Composite materials are utilized in many industries today due to its high performance and lightweight. However, the part manufacturing process of traditional composites is complicated and often involves high cost. The molds used for composite manufacturing are usually one of the contributors to the high part manufacturing cost. The authors demonstrated in this paper a manufacturing process for a carbon fiber reinforced composite rocket payload housing using an additively manufactured polylactic acid (PLA) payload housing core. The paper also demonstrates the designing and manufacturing of a functional product, which was used in a real-life application, achieved by college undergraduate students. …

Peridynamic Approaches For Damage Prediction In Carbon Fiber And Carbon Nanotube Yarn Reinforced Polymer Composites, Forrest E. Baber

Theses and Dissertations

Aerospace structures are increasingly utilizing advanced composites because of their high specific modulus and specific strength. While the introduction of these material systems can dramatically decrease weight, they pose unique certification challenges, often requiring extensive experimental testing in each stage of the design cycle. The expensive and time-consuming nature of experimental testing necessitates the advancement of simulation methodologies to both aid in the certification process and assist in the exploration of the microstructure design space.

Peridynamic (PD) theory, originating from Sandia National Lab’s in the early 2000’s, is a nonlocal continuum-based method that reformulates the equation of motion into an …

Aeroelasticity Of Composite Plate Wings Using Hsdt And Higher-Order Fem, Justin A. Haught

Graduate Theses, Dissertations, and Problem Reports (ETD)

The aeroelasticity of composite wings is becoming an increasingly researched topic in aircraft design, as designers continue to replace aluminum alloy components with those made of composite materials because of their favorable strength-to-weight ratio, fatigue characteristics, and corrosion resistance. Additionally, the bending-torsion coupling exhibited by composite laminates readily allow for the aeroelastic optimization of an aerodynamic structure through the process of aeroelastic tailoring. Wings made of composites materials, however, are more vulnerable to shear deformation.

The objective of the present research is to study the divergence and flutter characteristics of composite plate wings using a higher-order shear deformation theory (HSDT) …

Synthesis Of Graphene Using Plasma Etching And Atmospheric Pressure Annealing: Process And Sensor Development, Andrew Robert Graves

Graduate Theses, Dissertations, and Problem Reports (ETD)

Having been theorized in 1947, it was not until 2004 that graphene was first isolated. In the years since its isolation, graphene has been the subject of intense, world-wide study due to its incredibly diverse array of useful properties. Even though many billions of dollars have been spent on its development, graphene has yet to break out of the laboratory and penetrate mainstream industrial applications markets. This is because graphene faces a ‘grand challenge.’ Simply put, there is currently no method of manufacturing high-quality graphene on the industrial scale. This grand challenge looms particularly large for electronic applications where the …