Ultrasonic in-situ measurement method and error analysis of wear of PEEK water-lubricated bearing materials

• Published in: Measurement : journal of the International Measurement Confederation Vol. 214; p. 112822
• Main Authors: Hu, Fei, Ning, Changxiong, Ouyang, Wu
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.06.2023
• Subjects: Multi-parameter inversion; Particle swarm algorithm; Ultrasonic in-situ wear measurement; Water-lubricated polymer bearing; Ultrasonic in-situ wear measurement; Water-lubricated polymer bearing; Particle swarm algorithm; Multi-parameter inversion
• ISSN: 0263-2241; 1873-412X
• DOI: 10.1016/j.measurement.2023.112822

•An in-situ wear measurement method for polymer water-lubricated bearing based on ultrasound and parameter inversion was proposed. The wear could be identified by combining particle swarm optimization algorithm.•Influences of single-parameter to three-parameter on the objective function were simulated and analysed.•Wear test was conducted show that the parameter inversion of thickness, density and attenuation factor has the highest accuracy among all the multi-parameter inversions, with errors within 0.15%, 2% and 95%.•The precision of the thickness identification is gradually improved as the gain increases. The maximum error of thickness at 6 dB gain is 0.15%, which is 55% smaller than that without the gain. Water-lubricated polymer bearing is the key component to guarantee the function of ship propulsion systems, nuclear main pumps, hydraulic turbines and other important equipment. Abnormal wear of the water-lubricated polymer thrust bearing is a common failure under harsh working conditions such as low speed, heavy load, and sediment. Accurate acquisition of bearing wear is of great value for revealing the bearing wear mechanism and evaluating the bearing service life. Therefore, this paper proposes an in-situ measurement method of bearing wear based on ultrasound and parameter inversion. The objective function is defined as the correlation coefficient of the ultrasonic reflection coefficient amplitude spectrum. Different parameters, such as thickness, acoustic velocity, density and attenuation factor, are inverted by the particle swarm algorithm. Simulations are performed to analyze the influence of single-parameter to multi-parameter inversions on the objective function and the inversion of thickness. Taking the PEEK material as the subject, the experiment shows that the parameter inversion of thickness, density and attenuation factor has the highest accuracy, with errors within 0.15%, 2% and 95%, and the maximum absolute error of wear is 20 μm. If the amplitude of the reflected signal is small, the intensity of the transmission signal will affect the identification result of thickness.