This thesis describes an efficient procedure for calculating three dimensional resonant vibrations and stresses in intermediate and high pressure turbine blade groups. This procedure is capable of calculating all the natural frequencies, mode shapes, and bending stresses in the tangential, axial, and coupled modes of vibration. Simple beam theory is applied to develop a dynamic stiffness matrix. The solutions to this matrix give the natural frequencies and mode shapes for the blade group. Prohl's energy method is used to determine the amplitude of the forced vibrations and the dynamic stresses. A Goodman diagram fatigue criterion is applied to evaluate the probability of blade group failure. Comparing this procedure's numerical results with experimental results for a rectangular beam structure, the largest difference for the first five tangential natural frequencies is 1.2 percent. This method of analysis is simple and can be applied in twenty hours. Sample calculations and results are given for a typical blade group, and the advantages and limitations of this method are discussed.

Library of Congress Subject Headings

Turbines--Blades; Blades

Publication Date


Document Type


Department, Program, or Center

Mechanical Engineering (KGCOE)


Rieger, Neville

Advisor/Committee Member

Halbleib, William

Advisor/Committee Member

Walter, Wayne


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