Matching Items (274)
Description
Unidirectional glass fiber reinforced polymer (GFRP) is tested at four initial strain rates (25, 50, 100 and 200 s-1) and six temperatures (−25, 0, 25, 50, 75 and 100 °C) on a servo-hydraulic high-rate testing system to investigate any possible effects on their mechanical properties and failure patterns. Meanwhile, for the sake of illuminating strain rate and temperature effect mechanisms, glass yarn samples were complementally tested at four different strain rates (40, 80, 120 and 160 s-1) and varying temperatures (25, 50, 75 and 100 °C) utilizing an Instron drop-weight impact system. In addition, quasi-static properties of GFRP and glass yarn are supplemented as references. The stress–strain responses at varying strain rates and elevated temperatures are discussed. A Weibull statistics model is used to quantify the degree of variability in tensile strength and to obtain Weibull parameters for engineering applications.
ContributorsOu, Yunfu (Author) / Zhu, Deju (Author) / Zhang, Huaian (Author) / Huang, Liang (Author) / Yao, Yiming (Author) / Li, Gaosheng (Author) / Mobasher, Barzin (Author) / Ira A. Fulton Schools of Engineering (Contributor)
Created2016-05-19
Description
The meta-MAC protocol is a systematic and automatic method to dynamically combine any set of existing Medium Access Control (MAC) protocols into a single higher level MAC protocol. The meta-MAC concept was proposed more than a decade ago, but until now has not been implemented in a testbed environment due to a lack of suitable hardware. This thesis presents a proof-of-concept implementation of the meta-MAC protocol by utilizing a programmable radio platform, the Wireless MAC Processor (WMP), in combination with a host-level software module. The implementation of this host module, and the requirements and challenges faced therein, is the primary subject of this thesis. This implementation can combine, with certain constraints, a set of protocols each represented as an extended finite state machine for easy programmability. To illustrate the combination principle, protocols of the same type but with varying parameters are combined in a testbed environment, in what is termed parameter optimization. Specifically, a set of TDMA protocols with differing slot assignments are experimentally combined. This experiment demonstrates that the meta-MAC implementation rapidly converges to non-conflicting TDMA slot assignments for the nodes, with similar results to those in simulation. This both validates that the presented implementation properly implements the meta-MAC protocol, and verifies that the meta-MAC protocol can be as effective on real wireless hardware as it is in simulation.
ContributorsFlick, Nathaniel Graham (Author) / Syrotiuk, Violet (Thesis director) / Fainekos, Georgios (Committee member) / School of Mathematical and Statistical Sciences (Contributor) / Computer Science and Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
The capstone portion of this project was to use the established STaR antennas and add a Built in Self-Test system to ensure the quality of the signals being received. This part of the project required a MatLab simulation to be built, a layout created, and a PCB designed for fabrication. In theory, the test BiST unit will allow the gain and delay of the transmitted signal and then cancel out unneeded interference for the received signal. However, this design required multiple paths to maintain the same lengths to keep the signals in phase for comparison. The purpose of this thesis is to show the potential drop-offs of the quality of the signals from being out of phase due to the wires that should be similar, being off by a certain percentage. This project will calculate the theoretical delay of all wires being out of sync and then add this delay to the established MatLab simulation. This report will show the relationship between the error of the received variables and what the actual generated values. And, the last part of the document will demonstrate the simulation by creating a signal and comparing it to its received counterpart. The end result of the study showed that the percent error between what is seen and what is expected is near insignificant and, hence, not an issue with regards to the quality of the project.
ContributorsSomers, Tyler Scott (Author) / Ozev, Sule (Thesis director) / Kozicki, Michael (Committee member) / Electrical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
The purpose of the Simultaneous Transmit and Receive Antenna project is to design a test circuit that will allow us to use an antenna to both send out and receive a signal at the same time on the same frequency. The test circuit will generate DC voltage levels that we can use to solve for the gain and delay of the transmit interference, so we will then be able to cancel out the unwanted signal from the received signal. With a theoretically perfect setup, the transmitted signal will be able to be completely isolated from the received signal, leaving us with only what we want at the output. In practice, however, this is not the case. There are many variables that will affect the integrity of the DC output of the test signal. As the output voltage level deviates from its theoretical perfect measurement, the precision to which we are able to solve for the gain and delay values decreases. The focus of this study is to estimate the effect of using a digital measurement tool to measure the output of the test circuit. Assuming a voltmeter with 1 volt full range, simulations were run using measurements stored at different bit resolutions, from 8-bit storage up to 16-bit storage. Since the physical hardware for the Simultaneous Transmit and Receive test circuit is not currently available, these tests were performed with an edited version of the Matlab simulation created for the Senior Design project. The simulation was run 2000 times over each bit resolution to get a wide range of generated values, then the error from each run was analyzed to come to a conclusion on the effect of the digital measurement on the design. The results of these simulations as well as further details of the project and testing are described inside this document.
ContributorsKral, Brandon Michael (Author) / Ozev, Sule (Thesis director) / Kozicki, Michael (Committee member) / Electrical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05