  Contact interfaces with dry friction are frequently used in turbomachinery.
Dry friction damping produced by the sliding surfaces of these interfaces
reduces the amplitude of bladed-disk vibration. The relative displacements at
these interfaces lead to fretting-wear which reduces the average life
expectancy of the structure. Frequency response functions are calculated
numerically by using the multi-harmonic balance method (mHBM). The dynamic
Lagrangian frequency-time method is used to calculate contact forces in the
frequency domain. A new strategy for solving nonlinear systems based on dual
time stepping is applied. This method is faster than using Newton solvers. It
was used successfully for solving Nonlinear CFD equations in the frequency
domain. This new approach allows identifying the steady state of worn systems
by integrating wear rate equations a on dual time scale. The dual time
equations are integrated by an implicit scheme. Of the different orders tested,
the first order scheme provided the best results.
