In a gas turbine engine, the forced vibration of a turbine blade under resonant conditions is undesirable and may lead to premature high cycle fatigue failure. From the aspect of structural integrity, this demonstrates that it is extremely important to tune the excited vibration mode out of the operating speed range. This leads to the question: Is it possible to perform structural perturbations, namely to the mass and stiffness, in such a way that only the eigenvalue of choice significantly changes — while causing little or no change in the other natural frequencies? This is focus of the present paper. Due to the complexity of the blade structure, it is difficult to obtain an analytical solution from the eigenvalue perturbation theory. Nevertheless, the derived analytical expressions provide guidance from which the finite element method may successfully be applied as an alternative approach. This tuning approach is validated experimentally.

This content is only available via PDF.
You do not currently have access to this content.