Date of Award

9-18-2014

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Department of Aeronautics and Astronautics

First Advisor

Anthony N. Palazotto, PhD.

Abstract

This dissertation research produces the experimental techniques required to evaluate mistuning in any rotor. Within operation, a rotor is subjected to a unique pattern of frequencies acting to excite the rotor. Utilizing traveling wave excitation, a rotor's critical frequencies and the respective excitation pattern are reproduced. Individual rotor blade frequency response functions are evaluated and statistically analyzed. The experimental results serve to not only verify the degree to which a rotor is mistuned, but also to provide an indication of the forced response amplification the mistuning induces. Within the experiment, definitive specifications were developed to ensure peak rotor responses. Numerical simulations of the experiment were performed in ANSYS using a model developed by way of structured light scanning. With experimental and numerical eigenvalue differences of less than 1%, the unique modeling technique, capturing a rotor's geometric mistuning, is a valid method to predict a rotor's natural frequencies. Furthermore these same numerical results serve to validate the experimental free boundary assumption.

AFIT Designator

AFIT-ENY-DS-14-S-26

DTIC Accession Number

ADA609562

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