Friction Damping Modeling in High Stress Contact Areas Using Microslip Friction Model

It is well known that friction is really important to reduce amplitudes of vibration of rotor blades. Underplatform dampers are a common solution for introducing friction damping, but there are also other friction damping sources on blades that are produced in places with high normal loads and small relative displacements (e.g. lockplates and blade-disc joints). Several approaches based on the classical Coulomb friction law have been used in order to model the friction damping at those interfaces, but their results are not accurate enough for those cases with small displacements where high normal loads appear. This paper presents simulations of typical cases of friction on rotor blades (underplatform dampers, lockplates and blade root) using a method based on macroslip and the method developed by ‘Industria de TurboPropulsores’ (ITP) based on microslip (InTerPart MIcroslip COntact method), and their comparison with experimental results obtained with several tests performed at Imperial College London (IC). The comparison shows that, for cases with high normal loads and small displacements, the ITPMICO method obtains further more accurate results than based-on-macroslip one.Copyright © 2008 by ASME