Investigation of the combined effects of intentional mistuning,damping and coupling on the forced response of bladed disks

Abstract

Blade-to-blade mistuning is always inevitable in bladed disk assemblies due to imperfections in the manufacturing progress as well as wear during operation. As a result, the forced response of a mistuned bladed disk may be drastically larger than that of the nominal or tuned design. The attendant increase in stress can lead to premature high cycle fatigue (HCF) of the blades. Therefore, it is of great importance to predict and, ultimately, to reduce the blade forced response levels caused by mistuning. In this paper, intentional and random mistuning is introduced into a simplified 12-bladed disk model by varying the stiffness of the blades. The combined effects of intentional mistuning, damping and coupling are examined. The numerical results indicate that there is some threshold value of intentional mistuning and coupling that leads to maximum mistuning effects and certain relations among intentional mistuning strength, integer harmonics, damping and coupling can suppress the response levels of bladed disks with random mistuning, which provides useful guidelines for safe and reliable designs of bladed disk systems.

Keywords

Combined effects forced response intentional mistuning random mistuning

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References

Castanier MP and Pierre C. ( 1997) Consideration on the benefits of intentional blade mistuning for the forced response of turbomachinery rotors. ASME Publication AD 55: 419-425.

Castanier MP and Pierre C. ( 1998) Investigation of the combined effects of intentional and random mistuning on the forced response of bladed disks. AIAA Journal 98: 3720.

Castanier MP and Pierre C. ( 2006) Modeling and analysis of mistuned bladed disk vibration: status and emerging directions. Journal of Propulsion and Power 22(2): 384-396.

Crawley EF and Hall KC ( 1985) Optimization and mechanisms of mistuning in decades. ASME Journal of Engineering for Gas Turbines and Power 107(2): 629-643.

Slater JC , Gregory RM and Andrew JB ( 1999) Forced response of bladed disk assemblies. The Shock and Vibration Digest 31: 17-24.

Wang JJ , Li QH and Zhu ZG ( 2000) Vibratory localization of mistuned bladed disk assemblies-a review. Advances in Mechanics 30(4): 517-528.

Wei ST and Pierre C. ( 1988) Localization phenomena in mistuned assemblies with cyclic symmetry. Journal of Vibration, Acoustics, Stress and Reliability in Design 110: 429-449.

Yoo HH , Kim JY and Inman DJ ( 2003) Vibration localization of simplified mistuned cyclic structures undertaking external harmonic force. Journal of Sound and Vibration 261: 859-870.