Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 3 of 3
Full-Text Articles in Entire DC Network
Mechanical Testing And Evaluation Of Epoxy Resins At Cryogenic Temperatures, Justin Reed Jackson
Mechanical Testing And Evaluation Of Epoxy Resins At Cryogenic Temperatures, Justin Reed Jackson
Theses and Dissertations
The objective of this research is to develop a test methodology to be used in determining which material properties affect the ultimate performance of a composite overwrapped pressure vessel (COPV) at liquid nitrogen (LN2) temperatures. The test methodology being evaluated is based on that used for ambient performance of COPVs and includes: resin properties, resin/fiber interface and COPV burst data. The suitability of these tests at LN2 temperatures will be evaluated. The resin properties are investigated by use of tensile tests to determine: strain to failure (%å), failure stress (óys), and elastic modulus (E). TThe objective of this research is …
Cryogenic Shape Memory Alloy Actuators For Spaceport Technologies: Materials Characterization And Prototype Testing, Jennifer Lemanski
Cryogenic Shape Memory Alloy Actuators For Spaceport Technologies: Materials Characterization And Prototype Testing, Jennifer Lemanski
Electronic Theses and Dissertations
Shape memory alloys (SMAs) possess the unique ability to change their shape by undergoing a solid-state phase transformation at a particular temperature. The shape change is associated with a large strain recovery as the material returns to its "remembered" shape. Their ability to act as both sensor and actuator has made them an attractive subject of study for numerous applications. SMAs have many characteristics which are advantageous in space-related applications, including generation of large forces associated with the strain recovery, smooth and controlled movements, large movement to weight ratio, high reliability, and spark-free operation. The objective of this work is …
Super High-Speed Miniaturized Permanent Magnet Synchronous Motor, Liping Zheng
Super High-Speed Miniaturized Permanent Magnet Synchronous Motor, Liping Zheng
Electronic Theses and Dissertations
This dissertation is concerned with the design of permanent magnet synchronous motors (PMSM) to operate at super-high speed with high efficiency. The designed and fabricated PMSM was successfully tested to run upto 210,000 rpm The designed PMSM has 2000 W shaft output power at 200,000 rpm and at the cryogenic temperature of 77 K. The test results showed the motor to have an efficiency reaching above 92%. This achieved efficiency indicated a significant improvement compared to commercial motors with similar ratings. This dissertation first discusses the basic concept of electrical machines. After that, the modeling of PMSM for dynamic simulation …