The Application of the Recurrence Plot to Analyze Rubbing in An Unbalance Rotating Disk

This paper proposes the application of Recurrence Plot (RP) to analyze dry friction on mechanical rotating systems.

The construction of Recurrence Plots is based on the evaluation of the system dynamics represented in a phase plane. The phase plane represents the relationship between displacement and velocity; but in this case, the vibration signals are measured with accelerometers; thus the displacement and velocity function must be obtained integrating the field data. In this paper, a comparison of two integration methods is included, one of the methods is based on the Simpson’s integration, and the other is based on the empirical model decomposition (EMD) and the shifting principle of harmonic functions. The experiment consisted of a flexible rotor with an unbalance disk that rub a fixed plate. The tests included different operating speeds, keeping the unbalance constant. The vibrations were recorded with an accelerometer mounted on the rotor’s support and a laser vibrometer (LV) that measured the lateral displacements of the disk.

The results indicated that the RP patterns show significant differences when the friction load is applied, but only some quantification parameters reflect these differences. The RP were evaluated using quantitative parameters that highlighted the nonlinear effect caused by friction.