Sensor placement strategy for in-situ bearing defect detection

The placement of sensors is of critical importance to achieving high quality measurement for machine condition monitoring and fault diagnosis. This paper investigates sensor placement strategy for detecting structural defects of a ball bearing. Based on an analytical study of signal propagation from the defect location to the sensors, numerical simulations using a finite element algorithm were conducted to validate the signal strength at several representative sensor locations. The results were then experimentally verified through actual measurements. The study has shown that to achieve a high signal-to-noise ratio, the sensors need to be placed as closely as possible to the bearing, where signals due to structural defects are generated. The study has provided a theoretical framework for designing sensor-embedded bearings with built-in diagnostic capabilities