Effects of damping and varying contact area at blade-disc joints in forced response analysis of bladed disc assemblies

In this paper, an approach is developed to analyse the multiharmonic forced response of large-scale finite element models of bladed discs taking account of the nonlinear forces acting at the contact interfaces of blade roots. Area contact interaction is modelled by area friction contact elements which allow for friction stresses under variable normal load, unilateral contacts, clearances and interferences. Examples of application of the new approach to analysis of root damping and forced response levels are given and numerical investigations of effects of contact conditions at root joints and excitation levels are explored for practical bladed discs.