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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
181

ASSESSING THE IMPACT OF FIXANT SOLUTIONS APPLIED AT AIRCRAFT ACCIDENT SITES ON COMPOSITE FRACTOGRAPHIC EVIDENCE

Natalie Zimmermann (15322921) 19 April 2023 (has links)
<p>Composite materials used in the aviation industry are known to be more complex than their metallic predecessors. This impacts not only the design and manufacturing of composite structures, but also the failure studies when these structures fail and break (as may be the case in an aircraft accident). Additionally, when under combustion, composite materials introduce potential health hazards. At elevated temperatures, the fibers can be released, presenting an inhalation hazard. Similarly, the matrix decomposition results in a series of potentially toxic byproducts. When encountering composite fires at aircraft accident sites, a series of protocols have been delineated by the corresponding agencies. These include wearing personal protective equipment as well as the application of so-called fixant solutions over the burning composites, with the latter being the focus of this study. The purpose of the fixant solutions is to provide a film of protection that – in essence – holds down small fibers and prevents them from becoming airborne. While the use of fixant solutions is necessary to protect the health of individuals in the vicinity of burnt composites, the potential detrimental impact the application thereof has on fractographic evidence should also be considered. Experts in the field have voiced concerns regarding the use of fixants, outlining that these chemicals may wash evidence away, cover up evidence, or interfere with imaging methods needed during the failure analysis. The purpose of the conducted research, thus, was to compare the relative impact of four commonly used fixant solutions – namely water, wetted water, polyacrylic acid (PAA), as well as a mixture of water and floor wax – on fractographic features of failed carbon fiber/epoxy composite specimens. Specifically, fractographic evidence of two forms of damage – impact and tension – were evaluated. With this goal, the methodology included steps to manufacture the specimens of interest, introduce the two forms of damage, burn the specimens, apply fixants, and perform the microscopic analysis via a scanning electron microscope (SEM). The fractographic evidence prior and after the application of fixant was evaluated qualitatively and quantitatively. The results showed that the evaluated fixants did influence the fracture surfaces imaged, and in certain cased obscured evidence of interest. Additionally, differences between the fixants were ascertained for both forms of damage evaluated. The water treatment was found to perform the best, minimizing the disruption of evidence. Nonetheless, while the study did answer the research questions and the different treatments were compared, additional areas of research and factors that should be considered were identified. </p>
182

Transient temperature measurements in a ballistic impact experiment on a TORAY® TC1225 LMPAEK T700G thermoplastic composite material

Savadelis, Alexander 26 May 2023 (has links)
No description available.
183

Grain-Boundary Parameters Controlled Allotriomorphic Phase Transformations in Beta-Processed Titanium Alloys

Dixit, Vikas 21 May 2013 (has links)
No description available.
184

Isothermal Fatigue Life Prediction Techniques

Wertz, John Nicholas 24 May 2013 (has links)
No description available.
185

Determining the Mechanical Properties of Lattice Block Structures

Wilmoth, Nathan G. 05 June 2013 (has links)
No description available.
186

Understanding the Flow Physics of Shock Boundary-Layer Interactions Using CFD and Numerical Analyses

Friedlander, David J. 10 October 2013 (has links)
No description available.
187

Monitoring Damage Accumulation In SiC/SiC Ceramic Matrix Composites Using Electrical Resistance

Smith, Craig Edward 05 October 2009 (has links)
No description available.
188

Numerical Investigation of a Swirl Induced Flameless Combustor for Gas Turbine Applications

Sharma, Anshu January 2020 (has links)
No description available.
189

CFD Modeling of the Pyrolysis Reactor for CNT Synthesis

Anantharaman, Devanathan 23 August 2022 (has links)
No description available.
190

Prediction of Combustion Instabilities in a Non-Compact Flame via a Wave-Based Reduced Order Network Model

Hunter, Riley 22 August 2022 (has links)
No description available.

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