This paper deals with the characterization of the blade manufacturing geometric tolerances in order to get a given level of amplification in the forced response of a mistuned bladed-disk. The theory is based on the use of a nonparametric probabilistic model of blade random uncertainties. The dispersion parameters controlling the nonparametric model are estimated as a function of the geometric tolerances. The industrial application is devoted to the mistuning analysis of a 22 blades wide chord fan stage. Centrifugal stiffening due to rotational effects is also included. The results obtained validate the efficiency and the reliability of the method on three dimensional bladed disks.

To cite this version:Evangéline Capiez-Lernout, Christian Soize. Specifying manufacturing tolerances for a given amplification factor: a nonparametric probabilistic methodology. ASME. ASME Turbo Expo: Land, Sea and Air 2003, Jun 2003, Atlanta, Georgia, United States. ASME, GT-2003GT- -38050, pp. 1-12, 2003 ABSTRACTIt is known that the forced response of mistuned bladed disks can strongly be amplified in comparison with the forced response of the tuned system. The random character of mistuning thus requires the construction of probabilistics models of random uncertainties. This paper presents a nonparametric probabilistic model of random uncertainties which is adapted to the problematics of the blade mistuning. This nonparametric approach allows all the uncertainties yielding mistuning (manufacturing tolerances, dispersion of materials) to be taken into account and includes also the uncertainties due to the modeling errors. This new probabilistic model takes into account both the mistuning of the blade eigenfrequencies and the blade modal shapes. The first point concerns the construction of this nonparametric approach in order to perform a mistuning analysis. The second part is devoted to the inverse problem associated with the manufacturing tolerances. A relationship between the manufacturing tolerances and the level of mistuning is also constructed.