Development of prediction models of running-in attractor

- Running-in attractor was used to characterize the nonlinear state of friction system.
- Prediction models of running-in attractor were established.
- A self-adaptive pin holder was designed.

Running-in attractor is a stable and time-space ordered structure formed in running-in process. To establish prediction models of the running-in attractor, orthogonal experiments were performed by sliding pins against a disc during the running-in process. The attractors were reconstructed from the measured friction force signals. Their characteristic parameters were computed, and forming time was identified from phase trajectory plot. The variance analysis of characteristic parameters of running-in attractors was conducted to identify the primary and secondary factors for characteristic parameters. The models were established based on response surface method. The running-in attractor can be predicted by the models as long as the working conditions and the initial surfaces roughness are given, which provides reference to running-in design.