Finite element simulation of high cycle fretting wear using an implicit integration scheme and an adaptive cycle jump
Résumé
Among the various mechanical and chemical processes that can generate wear, fretting refers to small amplitude
cyclic tangential motion between two contacting solids. Wear under fretting motion happens in different
industrial contexts and can significantly reduce the lifetime of components. For example, such damage mode
could occur in pressurized water nuclear reactors between guide cards and control rods. Due to the diversity
of mechanisms at stake, modeling wear is complex, and predicting fretting wear by numerical approaches
raises some issues, especially due to non-linearities and the need to compute a very large number of time
steps. This explains why investigations still mainly rely on experimental approaches. In the present study, a
finite element model and a simulation strategy aiming at predicting fretting wear are presented. The model
represents a stainless steels cylinder/plane cyclic contact and the numerical results obtained are compared
with experimental data from the literature. The proposed simulation process is particularly suitable for
computing a high number of fretting cycles. To this end, a cycle jump technique is used in association with
different integration schemes. Results show that instabilities may arise on the computed pressure when an
explicit scheme is used, which limits the cycle jump. On the other hand, an implicit scheme ensures stable
computations but involves a trade-off between the possibility of considering a higher cycle jump and the number
of iterations required for convergence. Results show that the more cycles we perform, the faster the implicit
scheme converges. Therefore, the implicit scheme is especially appropriate for high-cycle computations. In
addition, an adaptive cycle jump is used with the implicit scheme, enabling to accelerate the computations
with a high number of cycles. The adaptive acceleration factor is obtained from an estimate of the wear profile
enlargement rate.
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