Vibration Characteristics of Hollow Symmetrical Blades Based on Thin Shell Theory

Abstract

This paper presents the results of investigating the vibrational characteristics of a hollow symmetrical blade based on thin shell theory which allows closed function representation of vibrational characteristics which are inaccessible using beam theory. A modified shell theory is presented and used for the analysis. The hollow blade is considered as a continuous system constructed from two cantilever circular cylindrical shells by matching the continuous boundary conditions. This technique is used to express the results in a continuous function analytical formation. The method presented is clearly for long hollow blades and does not require the computer storage of numerical methods. Comparison is made between the present technique, the beam theory, and experimental data for two laboratory models. The formulation can be extended to most types of blades and still retain the functional representation. This type of analysis may be quite useful when utilized judiciously with other methods such as finite elements.