Effects of Shear Deformation, Rotary Inertia, and Elasticity of the Support on the Resonance Frequencies of Short Cantilever Beams

The purpose of this paper is to contribute to the assessment of the influence of shear deformation, rotary inertia, and elasticity of the support on the resonance frequencies of short turbomachinery blades. To obtain defined test conditions and to model the stiffest possible root design, the study is made on beams and supports machined from one piece. Experimental results show good agreement with results obtained from the finite element program NASTRAN. An estimate of the combined effects obtained by taking the individual effects multiplicatively, with the effect of the elasticity of the support being computed on the basis of known static influence coefficients of the elastic half space, results in a frequency reduction larger than measured.