Constrained viscoelastic damping, test/analysis correlation on an aircraft engine

Abstract

Constrained viscoelastic damping treatments are fairly common in many applications but have not been industrially applied to aerospace engines. New engine designs tend to use BLISK (integrally bladed disks) machined from a single part and thus showing less friction damping than earlier designs. Constrained viscoelastic treatments are considered as a possible technology to enhance damping. The paper presents results of a modal test performed in an environmental chamber to highlight temperature sensitivity effects which are characteristic of viscoelastic treatments. In a second part the computational methodology used for simulations is presented. Meshing, model reduction and post-treatment issues will be addressed. The significant challenge is this problem is the computation of accurate strain levels in the viscoelastic layer for a large model with different symmetry for the disk and the constraining layer. Test analysis correlation at various temperatures will be presented showing good correlation for both the overall levels and the prediction of the influence of temperature. ©2010 Society for Experimental Mechanics Inc.