Characteristic Parameters and Evolution of the Running-in Attractor

Abstract

The running-in attractor is a chaotic attractor with stability, which forms in the running-in process. Its “formation-stabilization-disappearance” stage can reflect the dynamic features of the nonlinear friction system. To reveal the dynamic features and evolution of the running-in attractor, in this work, wear experiments are implemented on a ring-on-disk tribometer. The friction coefficient signals are then extracted and reconstructed. Based on the reconstructed matrix of the friction coefficient signals, the convergence (CON) and standard deviation of the distance matrix (STD) are proposed. Results show that CON evolves from an increase to the stabilization and then to a decrease. STD presents an inverse variation tendency, evolving from a decrease to the stabilization and then to an increase. A larger CON indicates higher convergence and a more complex friction system. A smaller STD indicates a more stable friction system. These two new characteristic parameters effectively exhibit the dynamic behavior of the wear process.