Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 4 of 4
Full-Text Articles in Engineering
Investigation Into Suitability Of Geopolymers (Illite & Metakaolin) For The Space Environment, Brandon T. Cesul
Investigation Into Suitability Of Geopolymers (Illite & Metakaolin) For The Space Environment, Brandon T. Cesul
Theses and Dissertations
Suitability of non-organic polymers for space application is studied. Materials included are illite and metakaolin. Bulk material suitability was investigated for exposure to ultraviolet radiation, atomic oxygen, and high energy charged particles. Outgassing phenomenon of the materials was studied. Curing shrinkage reduction techniques were identified as well.
Material Characterization For Composite Materials In Load Bearing Wave Guides, Gabriel Almodovar
Material Characterization For Composite Materials In Load Bearing Wave Guides, Gabriel Almodovar
Theses and Dissertations
This study will establish a methodology to examine samples of composite material for application in a load bearing waveguide. The composite material will operate in a specific frequency range for applications in small RPAs. A graphite epoxy stiffening component will be primarily considered. Different nickel, graphene, and carbon nanotube (CNT) coatings and films will be applied to the graphite epoxy. Tests will determine the material's radio frequency (RF) performance for application as an antenna/waveguide component. The study will use scattering (S) parameters determined from a network analyzer to collect these data. The S parameters will then be used to resolve …
Creep Of Hi-Nicalon S Ceramic Fiber Tows At Elevated Temperature In Air And In Steam, Benjamin R. Steffens
Creep Of Hi-Nicalon S Ceramic Fiber Tows At Elevated Temperature In Air And In Steam, Benjamin R. Steffens
Theses and Dissertations
Structural aerospace components require materials to have superior long-term mechanical properties that can withstand severe environmental conditions, such as high temperatures, high pressures and moisture, whilst enduring the loads they are designed for. Ceramic-matrix composites (CMCs) are capable of maintaining excellent strength and creep resistance at high temperatures, which make them attractive candidate materials for aerospace applications, particularly in propulsion. Silicon Carbide (SiC) ceramic fibers have been used as constituent materials in CMCs, although oxidation of the SiC to SiO2 has been a known degredation mechanism. Recently developed near stoichiometric SiC fibers have shown significant improvements in thermochemical stability; …
The Effect Of Elevated Temperature On The Inelastic Deformation Behavior Of Pmr-15 Solid Polymer, Chad E. C. Ryther
The Effect Of Elevated Temperature On The Inelastic Deformation Behavior Of Pmr-15 Solid Polymer, Chad E. C. Ryther
Theses and Dissertations
The inelastic deformation behavior of PMR-15 neat resin, a high-temperature thermoset polymer, was investigated at temperatures in the 274-316°C range. The experimental program was developed to explore the influence of temperature on tensile loading, relaxation and creep behaviors of PMR-15. The results demonstrate that the mechanical behavior of PMR-15 exhibits a strong dependence on temperature. During strain-controlled tensile loading, the slope of the stress-strain curve in the quasi-elastic region decreases and the flow stress level decreases with increasing temperature. During relaxation, the amount of the stress drop decreases with increasing temperature. Based on experimental results the Viscoplasticity Based on Overstress …