Honors Theses

Date of Award

Spring 5-2-2021

Document Type

Undergraduate Thesis

Department

Physics and Astronomy

First Advisor

Joel Mobley

Second Advisor

Cecille Labuda

Third Advisor

Craig Hickey

Relational Format

Dissertation/Thesis

Abstract

The purpose of this work was to identify and analyze the vibrational modes of a helical structure to model the vibrational characteristics of an L-band helical antenna for satellite communications. This project focused on the vibrational modes between 1 and 50 Hz. Using COMSOL Multiphysics finite element modeling of helices were performed to predict mode shapes and frequencies to compare with both continuous wave (CW) and impulsive measurements. In the initial phase of the experimental work, five helical samples were constructed and evaluated. In the second phase of the study, one sample was chosen for more detailed quantitative measurements. In the CW measurements, frequency sweeps between 1 and 50 Hz were conducted where excitations and measurements of both longitudinal and transverse responses were performed. The impulsive study utilized both the transverse and longitudinal excitations and measurements of both longitudinal and transverse responses were performed. The data were recorded under LabVIEW control and analyzed in MATLAB. The data show the predicted modes from the finite element modeling (FEM) study offered similar results to the experimental studies with differences ranging from 0.1 to 10%.

Accessibility Status

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