Abstract: The paper deals with dynamic response solution problem of shrouded bladed disc assemblies with dry friction.A hypothesis of multi-harmonic variables has been introduced into AFT method,so that its divergence problem due to alias and leakage error in iteration has been solved.This improved AFT method is independent of the harmonic number in variables of the friction number elements in the system.So it is a general method for solving dynamic response of a non-linear system.A model of cyclic two-dimensional substructure for a bladed disc has been calculated by this method,and the results have been compared with those of the direct integration method.