In-Situ Thermal And Deformation Characterization Of Additive Manufacturing Processes,
2023
Embry-Riddle Aeronautical University
In-Situ Thermal And Deformation Characterization Of Additive Manufacturing Processes, Nicholas Phillips
Doctoral Dissertations and Master's Theses
Additive manufacturing (AM) is a rapidly growing industry with numerous applications in the aerospace industry such as aircraft parts and emergency tools on the International Space Station. Defects in additively manufactured structures, however, can waste a lot of time and money. Being able to monitor the manufacturing process for defects is one of the first steps which can be taken to mitigate these losses. This study focuses on the use of thermography in conjunction with deep learning to identify flaws during 3D printing of composite structures made using Onyx, a mixture of chopped carbon fiber and nylon, composite prints. In …
Empowering Student Success: Unlocking The Potential Of Project-Based Steel Design Education,
2023
Louisiana State University
Empowering Student Success: Unlocking The Potential Of Project-Based Steel Design Education, Aly Mousaad Aly
Faculty Publications
In the pursuit of student success, it is essential to acknowledge that a singular teaching style does not universally cater to all students. The educator's crucial role lies in creating an optimal learning environment that fosters students' endeavors to excel. This endeavor transcends mere classroom success or employment prospects, encompassing a broader impact on societal well-being. An experiential learning approach, where students actively engage in practical tasks, emerges as the most effective mode of instruction. Integrating project-based learning activities into the curriculum holds immense potential for enhancing student learning. Additionally, the utilization of analysis software tools like FTool and STAAD …
Wast3d Potential,
2023
Rhode Island School of Design
Wast3d Potential, Andrew Larsen
Masters Theses
Waste is obsolete. Standard building industry practices are harmful to the environment. Non-traditional construction methods were examined as alternatives. Circular design logic was the guiding principle in material choice. Additive manufacturing is a proven modern method for building construction. Research on 3D printing case studies revealed that recycled plastic is a proven material and readily available. Removing plastic waste from the environment and sequestering it in architectural components gives the material a new purpose. The component of focus was a building block for a wall assembly. Inspiration was taken from the hexagonal Basalt rock formations found near volcanic fault lines. …
Improving The Tensile Mechanical Properties Of Direct Energy Deposited (Ded) Inconel 718 Aircraft Components Using A Standard Heat Treatment,
2023
California Polytechnic State University, San Luis Obispo
Improving The Tensile Mechanical Properties Of Direct Energy Deposited (Ded) Inconel 718 Aircraft Components Using A Standard Heat Treatment, Spencer Vincent Flynn
Materials Engineering
This project aimed to improve the mechanical properties of as-printed additively manufactured Inconel 718 samples using a heat treatment usually used for cast and wrought Inconel 718. The mechanical properties sought to be optimized were yield strength, ultimate tensile strength, elongation, and reduction in area. The property goals were to match or exceed those of cast and heat treated Inconel 718. Wire-fed electron beam direct energy deposition (DED) was used to manufacture the samples, which were then heat treated using the AMS 5663 standard in an inert atmosphere. The samples were then tested in tension to obtain data on their …
Feasibility Of Thermoplastic Extrusion Welding As A Joining Method For Vacuum-Assisted Additively Manufactured Tooling,
2023
University of Maine
Feasibility Of Thermoplastic Extrusion Welding As A Joining Method For Vacuum-Assisted Additively Manufactured Tooling, Chase C. Flaherty
Electronic Theses and Dissertations
In recent years, additive manufacturing (AM) has been successfully utilized for the production of large-scale composite tooling. Within these endeavors, however, limited research has focused on joining methods between printed sections. This work evaluates the feasibility of thermoplastic extrusion welding as a joining method for additively manufactured tooling structures. This joining method was assessed based on industry specifications of conventional thermoset tooling for wind blade manufacturing utilizing the vacuum-assisted resin transfer molding (VARTM) process. The specifications include requirements for the mechanical strength, vacuum integrity, roughness, and hardness of the tool surface. The feasibility of this welded polymer joint was demonstrated …
Investigation Into Sintered Lunar Regolith Construction Methods And Novel Usability Evaluation,
2023
University of Maine
Investigation Into Sintered Lunar Regolith Construction Methods And Novel Usability Evaluation, Thomas A. Cox
Electronic Theses and Dissertations
Since the Apollo missions in the late 1960's, there has been a growing interest shared by many countries around the world to return to the Moon and establish a permanent Lunar settlement. The first phase of temporary Lunar bases will be established over the next several years. For a permanent human presence on the Moon, it will be necessary to use locally available resources for the construction of Lunar habitats and other infrastructure. Sintering Lunar regolith has been shown to be a promising method for producing structural material with a variety of desirable properties from strength to radiation shielding. While …
Classification Of Electrical Current Used In Electroplastic Forming,
2023
Clemson University
Classification Of Electrical Current Used In Electroplastic Forming, Tyler Grimm
All Dissertations
Electrically assisted manufacturing (EAM) is the direct application of an electric current to a workpiece during manufacturing. This advanced manufacturing process has been shown to produce anomalous effects which extend beyond the current state of modeling of thermal influences. These purported non-thermal effects have collectively been termed electroplastic effects (EPEs).
While there is a distinct difference in results between steady-state (ideal DC) testing and pulsed current testing, the very definition of these two EAM methods has not been well established. A "long" pulse may be considered DC current; a "short" pulse may produce electroplastic effects; and even "steady-state" current shapes …
A Systematic Study Into The Design And Utilization Of Burn Wire As A Means Of Tensioning And Releasing Spacecraft Mechanisms Through Applied Joule Heating,
2023
University of Arkansas, Fayetteville
A Systematic Study Into The Design And Utilization Of Burn Wire As A Means Of Tensioning And Releasing Spacecraft Mechanisms Through Applied Joule Heating, Chandler Dye
Mechanical Engineering Undergraduate Honors Theses
The joule heating characteristics of Nichrome burn wires, often used as a thermal cutting device in mechanisms designed to fasten and release CubeSat deployables, are examined in the following thesis. Wires ranging from 0.125 inches to 2 inches long, and diameters of 30 Ga and 40 Ga, are investigated through analytical calculations and thermal simulations based on heat transfer due to joule heating, and through physical circuitry-based experiments. The temperature data is used to generate heating curves to predict the time it takes for Nichrome wires to fail under varying testing parameters. This research aims to catalog a series of …
Superfly Amphibian,
2023
Kennesaw State University
Superfly Amphibian, Devonte Andrews, Ahmed Hamza, Kwesi Onumah, Eva Sanchez
Senior Design Project For Engineers
Following a Short Takeoff and Landing (STOL) mission profile, this seaplane is designed to carry 19 passengers and 1 flight crew with a range of 200 nautical miles. The seaplane is equipped with two turbo-prop engines and is economically comparable to current seaplanes in terms of servicing and operating expenses. The aircraft is capable of operating in remote locations with limited infrastructure due to its STOL abilities, allowing for increased access to difficult-to-reach areas. The seaplane's design incorporates modern materials and technologies to enhance efficiency, safety, and comfort for passengers and crew. The aircraft's versatility and cost-effectiveness make it an …
Effects Of Tempering Temperature On Gas Turbine Fan Cases,
2023
University of Connecticut
Effects Of Tempering Temperature On Gas Turbine Fan Cases, Seth Utter
Honors Scholar Theses
The project aimed to investigate the effects of tempering temperature on metals used for gas turbine engine fan cases as a major relevant concern is containing blades in during blade-out events. There are three ways to accomplish this: using a thicker metal, incorporating different materials into the case, or heat treating the metal. This project focused on the third solution: reviewing the impact toughness and hardness of fractured samples and their equivalent ductile-to-brittle transition shear faces. Given its availability, 1045 steel, as opposed to aerospace grade metals, was used for in-house testing. The data obtained from these experiments were then …
Characterization Of Bistability Behavior In Unsymmetric Cfrp Laminates,
2023
Embry-Riddle Aeronautical University
Characterization Of Bistability Behavior In Unsymmetric Cfrp Laminates, Evan Medora
Doctoral Dissertations and Master's Theses
Composite laminates of unsymmetric layup families often exhibit twin stable shapes at room temperature, a phenomenon known as bistability. Unsymmetric bistable composite laminates have often been suggested for applications in aerospace morphing structures, damping, and energy storage, because of their ability to easily change their shape while being homogenized with the rest of the composite structure.
This study analyzes the mechanisms responsible for bistability in unsymmetrical [0/0/90/90] laminates through a combination of experiments and modeling. Several unsymmetrical laminates with different aspect ratios were fabricated using autoclave processing. Digital image correlation (DIC) is used to monitor laminate strains in situ during …
The Role Of Slip System Activation On Ni-Based Superalloy High Temperature Fatigue,
2023
Embry-Riddle Aeronautical University
The Role Of Slip System Activation On Ni-Based Superalloy High Temperature Fatigue, Alexandru Lopazan
Doctoral Dissertations and Master's Theses
Nickel-based superalloys are used extensively in the aviation industry, particularly in aircraft engine components. These materials are desirable due to their high strength, resistance to creep, corrosive environment, and high temperature. It has been well documented that material fatigue is characterized by material microstructure, type of loading, and other parameters. Currently, research into the effects of fatigue on complex materials like nickel-based superalloys is being pursued. Previous research has found that preconditioning of Inconel 718 samples at 700 ℃ with 1.0% strain led to an improved fatigue life. It has been suggested that this could be caused by the activation …
Study Of Nanocomposite Materials Using Molecular Dynamics,
2023
Michigan Technological University
Study Of Nanocomposite Materials Using Molecular Dynamics, Prashik Sunil Gaikwad
Dissertations, Master's Theses and Master's Reports
There is an increase in demand for new lightweight structural materials in the aerospace industry for more efficient and affordable human space travel. Polymer matrix composites (PMCs) with reinforcement material as carbon nanotubes (CNTs) have shown exceptional increase in the mechanical properties. Flattened carbon nanotubes (flCNTs) are a primary component of many carbon nanotube (CNT) yarn and sheet materials, which are promising reinforcements for the next generation of ultra-strong composites for aerospace applications. These flCNT/polymer materials are subjected to extreme pressure and temperature during curing process. Therefore there is a need to investigate the evolution of properties during the curing …
Surface Preparation Study,
2023
The University of Akron
Surface Preparation Study, Ryan Ferguson
Williams Honors College, Honors Research Projects
This work explores a custom air atmospheric pressure plasma treatment (APPT) machine’s effectiveness in cleaning and chemically activating a CFRP surface. It is explore by implementing water contact angle (WCA) measurements, water-break free (WBF) testing, and adhesive tubular lap-joint (TLJ) tensile testing. An 8x3 test matrix of different machine parameters is defined with the bounding conditions being the machine’s capabilities and industry standard recommendations. Each configuration of the test matrix is explored after treatment at multiple time intervals up to 2 weeks afterwards to gain insight into the outlife of the treatments with the intention of adhesively bonding to the …
Impact Of Spallation And Internal Radiation On Fibrous Ablative Materials,
2023
University of Kentucky, Lexington
Impact Of Spallation And Internal Radiation On Fibrous Ablative Materials, Raghava Sai Chaitanya Davuluri
Theses and Dissertations--Mechanical Engineering
Space vehicles are equipped with Thermal Protection Systems (TPS) that encounter high heat rates and protect the payload while entering a planetary atmosphere. For most missions that interest NASA, ablative materials are used as TPS. These materials undergo several mass and energy transfer mechanisms to absorb intense heat. The size and construction of the TPS are based on the composition of the planetary atmosphere and the impact of various ablative mechanisms on the flow field and the material. Therefore, it is essential to quantify the rates of different ablative phenomena to model TPS accurately. In this work, the impact of …
Determination Of Damage Initiation Mechanisms In Aerospace Alloys Due To Stress Corrosion Cracking Via In-Situ Microscale Characterization Techniques,
2023
University of Central Florida
Determination Of Damage Initiation Mechanisms In Aerospace Alloys Due To Stress Corrosion Cracking Via In-Situ Microscale Characterization Techniques, Remelisa Esteves
Electronic Theses and Dissertations, 2020-
Aluminum alloys are used on aerospace vehicles due to their high strength-to-weight ratio, formability and machinability. However, they become vulnerable to stress corrosion cracking (SCC) during their service life. SCC is primarily caused by the material's stress condition, a suitable corrosive environment and material susceptibility. It is also influenced by a mixture of electrochemical, mechanical, and chemical factors. Due to the complexity of SCC, tools with better resolution and sensitivity are needed to better understand the impact and interaction of the contributing factors. A vast amount of research has been done to study SCC behavior, but the scale of characterization …
Computational And Experimental Investigation Of Mass Reduced Aircraft Wing Ribs,
2023
Georgia Southern University
Computational And Experimental Investigation Of Mass Reduced Aircraft Wing Ribs, Charles R. Fricks Iii
Electronic Theses and Dissertations
This study seeks to develop and evaluate a novel design of mass reduced aircraft wing ribs through the topology optimization method. For comparison, the same examination is performed on ribs with normal internal geometry. The wing rib design is based on that of the Gulfstream G650 transonic jet. The rib was divided into three segments for analysis based around the positions of the two spars. Only the center section of the rib (that being between the forward and aft spars) is mass optimized, while the leading and trailing edges of the ribs (outside the spars) will be kept solid for …
Application Of Multi-Scale Computational Techniques To Complex Materials Systems,
2023
University of Kentucky
Application Of Multi-Scale Computational Techniques To Complex Materials Systems, Mujan N. Seif
Theses and Dissertations--Chemical and Materials Engineering
The applications of computational materials science are ever-increasing, connecting fields far beyond traditional subfields in materials science. This dissertation demonstrates the broad scope of multi-scale computational techniques by investigating multiple unrelated complex material systems, namely scandate thermionic cathodes and the metallic foam component of micrometeoroid and orbital debris (MMOD) shielding. Sc-containing "scandate" cathodes have been widely reported to exhibit superior properties compared to previous thermionic cathodes; however, knowledge of their precise operating mechanism remains elusive. Here, quantum mechanical calculations were utilized to map the phase space of stable, highly-faceted and chemically-complex W nanoparticles, accounting for both finite temperature and chemical …
Characterizing Air Plasma Sprayed Aluminum Oxide Coatings For The Protection Of Structures In Lunar Environments,
2023
University of Central Florida
Characterizing Air Plasma Sprayed Aluminum Oxide Coatings For The Protection Of Structures In Lunar Environments, Perla Latorre Suarez
Electronic Theses and Dissertations, 2020-
Wear-resistant ceramic and ceramic composite coatings are significant to provide durability and support long-duration missions to the moon's surface for rovers, landers, robotic systems, habitats, and many other components. On the Lunar surface, structural components are continuously exposed to lunar dust projectiles that can cause protective coating delamination around the affected area, of protective coatings and this may not be physically visible. Ceramic coatings, composed of alumina, present excellent resistance to different types of wear due to their high strength and hardness as well as the ability to protect structural components from regolith impacts, wear, and abrasive damage. Air Plasma …
Energy Dissipation In A Sand Damper Under Cyclic Loading,
2022
Southern Methodist University
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 eort 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 …
