The water-lubricated thrust bearings of the marine rim-driven thruster (RDT) are usually composed of polymer composites, which are prone to serious wear under harsh working conditions. Ultrasonic is an excellent non-destructive monitoring technology, but polymer materials are characterized by viscoelasticity, heterogeneity, and large acoustic attenuation, making it challenging to extract ultrasonic echo signals. Therefore, this paper proposes a wear monitoring method based on the amplitude spectrum of the ultrasonic reflection coefficient. The effects of bearing parameters, objective function, and algorithm parameters on the identification results are simulated and analyzed. Taking the correlation coefficient and root mean square error as the matching parameters, the thickness, sound velocity, density, and attenuation factor of the bearing are inversed simultaneously by utilizing the differential evolution algorithm (DEA), and the wear measurement system is constructed. In order to verify the identification accuracy of this method, an accelerated wear test under heavy load was executed on a multi-functional vertical water lubrication test rig with poly-ether-ether-ketone (PEEK) fixed pad and stainless-steel thrust collar as the object. The thickness of pad was measured using the high-precision spiral micrometer and ultrasonic testing system, respectively. Ultimately, the results demonstrate that the thickness identification error of this method is approximately 1%, and in-situ monitoring ability will be realized in the future, which is of great significance to the life prediction of bearings.

船用轮缘驱动推进器（RDT）的水润滑推力轴承通常由聚合物复合材料制成，在恶劣的工作条件下容易出现严重磨损。超声波是一种优秀的无损监测技术，但高分子材料具有粘弹性、非均质性、声衰减大等特点，使得超声回波信号的提取具有挑战性。为此，本文提出了一种基于超声反射系数幅值谱的磨损监测方法。仿真分析了轴承参数、目标函数和算法参数对辨识结果的影响。以相关系数和均方根误差为匹配参数，厚度、声速、密度、利用微分进化算法(DEA)同时反演轴承的磨损系数和衰减系数，构建磨损测量系统。为验证该方法的识别精度，在聚醚醚酮（PEEK）固定垫和不锈钢止推环多功能立式水润滑试验台上进行了重载加速磨损试验。物体。焊盘厚度分别采用高精度螺旋测微仪和超声波检测系统进行测量。最终结果表明，该方法的厚度识别误差约为1%，且 为验证该方法的识别精度，在聚醚醚酮（PEEK）固定垫和不锈钢止推环多功能立式水润滑试验台上进行了重载加速磨损试验。物体。焊盘厚度分别采用高精度螺旋测微仪和超声波检测系统进行测量。最终结果表明，该方法的厚度识别误差约为1%，且 为验证该方法的识别精度，在聚醚醚酮（PEEK）固定垫和不锈钢止推环多功能立式水润滑试验台上进行了重载加速磨损试验。物体。焊盘厚度分别采用高精度螺旋测微仪和超声波检测系统进行测量。最终结果表明，该方法的厚度识别误差约为1%，且未来将实现原位监测能力，这对轴承的寿命预测具有重要意义。