Real-time stress evolution inner water-lubricated bearings (WLBs) in service time is unaware due to its installation position and harsh surroundings on ship, which will be of vital importance for identifying bearing fault such as abnormal wear or frictional noise. In this work, we present an embeddable sensor based on fibre Bragg gratings (FBGs) and applicate it for bearing internal stress characterization. The developed sensor shows excellent sensing accuracy and repeatability. Integrating FBG sensors into a full-size WLB achieves the static and dynamic stress monitoring in test rig experiments. Stress distribution along bearing axis was revealed. Dynamic stress inner bottom lining was recorded and analyzed during running-in, pulse excitation, load or rotary speed tests as well as start-up/stop experiments. The outcome indicates that FBG sensors are able to readily detect external impact on shaft and nicely monitor stress variation inner bearing lining. Averaged stress and its variation amplitude reduce with shaft speed rising. It is also interesting to note that the periodically dynamic stress in lining is consistent with shaft speed, which can even reflect shaft speeding up/down. This study provides a novel strategy of utilizing FBG for status monitoring and fault diagnose of WLBs.

中文翻译：

---

嵌入式光纤布拉格光栅全尺寸水润滑轴颈轴承内应力原位监测实验研究


由于安装位置和船上恶劣的环境，内部水润滑轴承（WLB）在使用过程中的实时应力演变是无法察觉的，这对于识别异常磨损或摩擦噪声等轴承故障至关重要。在这项工作中，我们提出了一种基于光纤布拉格光栅（FBG）的嵌入式传感器，并将其应用于轴承内应力表征。所开发的传感器具有出色的传感精度和重复性。将 FBG 传感器集成到全尺寸 WLB 中，实现了试验台实验中的静态和动态应力监测。显示了沿轴承轴线的应力分布。在磨合、脉冲激励、负载或转速测试以及启动/停止实验期间记录和分析内底衬的动态应力。结果表明，FBG 传感器能够轻松检测轴上的外部冲击，并很好地监控轴承衬内的应力变化。平均应力及其变化幅度随着轴转速的升高而减小。有趣的是，衬里的周期性动态应力与轴速度一致，甚至可以反映轴的加速/减速。本研究提供了一种利用 FBG 进行 WLB 状态监测和故障诊断的新策略。