Evaluation of Vibration Characteristics Signatures for Condition Monitoring of Rotor Bearing System by Using Box-Behnken Experimental Design

Abstract To address the complexity of vibration in ball bearings with composite defects during actual operation, bearings play an imperative role in ensuring the smooth, low friction operation of rotating machinery by reducing friction. Bearings operating within the low to medium speed range are commonly used in a wide variety of industrial, automotive, and machinery applications. This paper proposes a dynamic model for the complex, combined effects of load, localized defects, and misalignment on the vibration characteristics of rotor-bearing systems. To establish a robust theoretical framework, dimensional analysis using the matrix method was first employed to identify the principal dimensionless groups governing the system's dynamic behaviour. Finally, the model proposed is verified by experiments, and the influence of misalignment, speeds, defect sizes, and loads on the vibration characteristics of the bearing is investigated. Response Surface Methodology (RSM), specifically a Box-Behnken Design (BBD), was implemented to systematically plan the experiments and quantify the interaction effects between the input variables. Vibration amplitudes were recorded under various combinations of applied load, defect severity, and misalignment levels. The BBD analysis provides a comprehensive model of the system's response, confirming that increases in both load and misalignment significantly elevate vibration amplitudes. The work of this paper can improve the accuracy of rotor compound fault identification and provide references for vibration control of rotating machines, fault diagnosis, and life prediction.