TY - GEN
T1 - Effects of harmonic intentional mistuning on the free response of bladed disks
AU - Brewer, Michael E.
AU - Castanier, Matthew P.
AU - Pierre, Christophe
N1 - Publisher Copyright:
© 1999 by ASME
PY - 1999
Y1 - 1999
N2 - In this paper, the free response of bladed disks with intentional mistiming is considered in detail. A simple lumped-parameter model of a bladed disk is employed. Intentional mistuning is included by applying a sinusoidal variation to the nominal blade stiffnesses. It is shown that if the intentional mistuning harmonic number and the number of blades have a common integer factor greater than one, then the eigenvalue problem reduces to a set of smaller problems. It is found that the ratio of intentional mistuning strength to the interblade coupling strength is a key parameter for the free response. As this ratio increases, the modes become localized. More importantly, the modes of the intentionally mistuned system have several non-zero nodal diameter components, in contrast to the tuned system which has pure nodal diameter modes. Furthermore, if only random mistuning is present, each mode of the bladed disk assembly still retains a strong nodal diameter component. However, the modes of the system with intentional mistuning and random mistuning tend to have more evenly distributed nodal diameter components. This shows why intentional mistuning can be effective in reducing the maximum blade forced response for engine order excitation.
AB - In this paper, the free response of bladed disks with intentional mistiming is considered in detail. A simple lumped-parameter model of a bladed disk is employed. Intentional mistuning is included by applying a sinusoidal variation to the nominal blade stiffnesses. It is shown that if the intentional mistuning harmonic number and the number of blades have a common integer factor greater than one, then the eigenvalue problem reduces to a set of smaller problems. It is found that the ratio of intentional mistuning strength to the interblade coupling strength is a key parameter for the free response. As this ratio increases, the modes become localized. More importantly, the modes of the intentionally mistuned system have several non-zero nodal diameter components, in contrast to the tuned system which has pure nodal diameter modes. Furthermore, if only random mistuning is present, each mode of the bladed disk assembly still retains a strong nodal diameter component. However, the modes of the system with intentional mistuning and random mistuning tend to have more evenly distributed nodal diameter components. This shows why intentional mistuning can be effective in reducing the maximum blade forced response for engine order excitation.
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U2 - 10.1115/DETC99-VIB-8012
DO - 10.1115/DETC99-VIB-8012
M3 - Conference contribution
AN - SCOPUS:10244233747
T3 - Proceedings of the ASME Design Engineering Technical Conference
SP - 1873
EP - 1884
BT - 17th Biennial Conference on Mechanical Vibration and Noise
T2 - ASME 1999 Design Engineering Technical Conferences, DETC 1999
Y2 - 12 September 1999 through 16 September 1999
ER -