Type of Document	Master's Thesis
Author	Collins, J. Scott
URN	etd-02062013-040146
Title	Static and free-vibrational response of semi-circular graphite- epoxy frames with thin-walled open sections
Degree	Master of Science
Department	Aerospace and Ocean Engineering
Advisory Committee	Advisor Name Title Johnson, Eric R. Committee Chair Griffin, Odis Hayden Jr. Committee Member Hyer, Michael W. Committee Member Kapania, Rakesh K. Committee Member
Keywords	Structural frames
Date of Defense	1989-10-05
Availability	restricted
Abstract Experiments were conducted to measure the three-dimensional static and free vibrational response of two graphite-epoxy, thin-walled, open section frames. The frames are semi-circular with a radius of three feet, and one specimen has an I cross section and the other has a channel cross section. The flexibility influence coefficients were measured in static tests for loads applied at midspan with the ends of the specimens clamped. Natural frequencies and modes were determined from vibrational tests for free and clamped end conditions. The experimental data is used to evaluate a new finite element which was developed specifically for the analysis of curved, thin-walled structures. The formulatio of the element is based on a Vlaysov-type, thin-walled, curved beam theory. The predictions from the finite element program generally correlated well with the experimental data for the symmetric I-specimen. Discrepancies in some of the data were found to be due to flexibility in the ’clamped' end conditions. With respect to the data for the channel specimen, the correlation was less satisfactory. The finite element analysis predicted the out-of-plane response of the channel specimen reasonably well, but large discrepancies occurred between the predicted in-plane response and the experimental data. The analysis predicted a much more compliant in-plane response then was observed in the experiments.
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