Epureanu Research Group

Frictional dampers have been introduced to reduce the forced responses amplified by mistuning (Fig 3). However, the damper design process often targets a model of a tuned blisk. The effectiveness of such dampers, when mistuning is present, is unknown. It is necessary to investigate the correlation between the effectiveness of frictional damping and various types of mistuning.

Non-linear structural analyses directly performed on the finite element models of blisk-damper systems can be computationally expensive. In this research project, the main objective is to develop a reduced-order modeling technique that can efficiently and accurately predict the forced responses of a mistuned blisk in contact with frictional dampers. The technique is used to as the first method that is capable of conducting statistical analyses to study the mutual effect between random mistuning and frictional damping.


	Reduced-Order Modeling of Frictionally Damped Blisks with Simultaneous Small Material Mistuning and Large Geometric Damage

	A bladed disk (or blisk) is a turbomachinery component comprising both a disk and several blade components (Fig 1). Ideally, all blade components possess identical structural properties. However, in practice, mistuning, defined as the deviation of structural properties of each individual sector, exists in nearly all blisks. Mistuning can be as small as tiny fractional changes in material properties, or as catastrophic as large volumes of missing material. Mistuning often leads to strain energy localization and drastic increase in forced responses (Fig 2). Frictional dampers have been introduced to reduce the forced responses amplified by mistuning (Fig 3). However, the damper design process often targets a model of a tuned blisk. The effectiveness of such dampers, when mistuning is present, is unknown. It is necessary to investigate the correlation between the effectiveness of frictional damping and various types of mistuning. Non-linear structural analyses directly performed on the finite element models of blisk-damper systems can be computationally expensive. In this research project, the main objective is to develop a reduced-order modeling technique that can efficiently and accurately predict the forced responses of a mistuned blisk in contact with frictional dampers. The technique is used to as the first method that is capable of conducting statistical analyses to study the mutual effect between random mistuning and frictional damping.