Barrett

Barrett, The Honors College at Arizona State University proudly showcases the work of undergraduate honors students by sharing this collection exclusively with the ASU community.

Barrett accepts high performing, academically engaged undergraduate students and works with them in collaboration with all of the other academic units at Arizona State University. All Barrett students complete a thesis or creative project which is an opportunity to explore an intellectual interest and produce an original piece of scholarly research. The thesis or creative project is supervised and defended in front of a faculty committee. Students are able to engage with professors who are nationally recognized in their fields and committed to working with honors students. Completing a Barrett thesis or creative project is an opportunity for undergraduate honors students to contribute to the ASU academic community in a meaningful way.

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Improving damage detection and localization in complex composites

Description
The goal of this research is to couple a physics-based model with adaptive algorithms to develop a more accurate and robust technique for structural health monitoring (SHM) in composite structures. The purpose of SHM is to localize and detect damage in structures, which has broad applications to improvements in aerospace…

The goal of this research is to couple a physics-based model with adaptive algorithms to develop a more accurate and robust technique for structural health monitoring (SHM) in composite structures. The purpose of SHM is to localize and detect damage in structures, which has broad applications to improvements in aerospace technology. This technique employs PZT transducers to actuate and collect guided Lamb wave signals. Matching pursuit decomposition (MPD) is used to decompose the signal into a cross-term free time-frequency relation. This decoupling of time and frequency facilitates the calculation of a signal's time-of-flight along a path between an actuator and sensor. Using the time-of-flights, comparisons can be made between similar composite structures to find damaged regions by examining differences in the time of flight for each path between PZTs, with respect to direction. Relatively large differences in time-of-flight indicate the presence of new or more significant damage, which can be verified using a physics-based approach. Wave propagation modeling is used to implement a physics based approach to this method, which is coupled with adaptive algorithms that take into account currently existing damage to a composite structure. Previous SHM techniques for composite structures rely on the assumption that the composite is initially free of all damage on both a macro and micro-scale, which is never the case due to the inherent introduction of material defects in its fabrication. This method provides a novel technique for investigating the presence and nature of damage in composite structures. Further investigation into the technique can be done by testing structures with different sizes of damage and investigating the effects of different operating temperatures on this SHM system.
ContributorsBarnes, Zachary Stephen (Author) / Chattopadhyay, Aditi (Thesis director) / Neerukatti, Rajesh Kumar (Committee member) / Barrett, The Honors College (Contributor) / Department of English (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2015-05
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STRUCTURAL HEALTH MONITORING OF FIBER REINFORCED COMPOSITE STRUCTURES UNDER HIGH VELOCITY IMPACT LOADS

Description
This thesis encompasses research performed in the focus area of structural health monitoring. More specifically, this research focuses on high velocity impact testing of carbon fiber reinforced structures, especially plates, and evaluating the damage post-impact. To this end, various non-destructive evaluation techniques such as ultrasonic C-scan testing and flash thermography…

This thesis encompasses research performed in the focus area of structural health monitoring. More specifically, this research focuses on high velocity impact testing of carbon fiber reinforced structures, especially plates, and evaluating the damage post-impact. To this end, various non-destructive evaluation techniques such as ultrasonic C-scan testing and flash thermography were utilized for post-impact analysis. MATLAB algorithms were written and refined for the localization and quantification of damage in plates using data from sensors such as piezoelectric and fiber Bragg gratings sensors. Throughout the thesis, the general plate theory and laminate plate theory, the operations and optimization of the gas gun, and the theory used for the damage localization algorithms will be discussed. Additional quantifiable results are to come in future semesters of experimentation, but this thesis outlines the framework upon which all the research will continue to advance.
ContributorsMccrea, John Patrick (Author) / Chattopadhyay, Aditi (Thesis director) / Borkowski, Luke (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor) / Department of Military Science (Contributor)
Created2015-05