基于光纤光栅传感技术的门座式起重机SHM实施

Gantry Crane SHM Implementation Strategy Based on Fiber Grating Sensing Technology

结构健康监测(SHM)技术能在线实时监测结构健康情况、切实提高设备安全性能而日益引起人们的关注。将光纤光栅传感技术引入起重机SHM中,以一台MQ2533门座式起重机为试点,以有限元方法得出结构应力集中点作为传感器布点依据。采用32个光纤光栅传感器,通过光路复用成11路传感通道进行实时应变数据的采集。针对光纤光栅传感器温度和应变的交叉敏感问题,推导出光纤光栅温度式传感器和应变式传感器的一次线性拟合算法。利用该算法编写结构健康监测与安全预警软件平台。通过有限元计算得到关键点和重要点能够承受的最大应力,并给予一定的余量,计算出了各个关键点的预警值和报警值。经过半年多的运行,表明所开发的基于光纤光栅传感技术的门座式起重机结构健康监测系统能较好地实时在线监测起重机的结构状况,在发生危险前能发出预警信息。

Crane structural health monitoring （SHM） has attracted much attention. Fiber grating sensing （FBG） technology is used in crane SHM in our program. Taking MQ2533 as the first experiment, according calcu- lating key parts maximum stress by the means of FEM, 32 FBG sensors which is consisted of 11 channels were used. They were used for real time data acquisition. In addition, the distribution program and its location were giv- en, and FBG lead length was also calculated by the use of assembly drawings and parts drawings. Due to the cross sensitive issues of FBG temperature and strain, one-linear fitting formula of FBG temperature sensors and strain sen-sors. Furthermore, the structural health monitoring and safety warning software platform was set by these one-linear fitting formulas are derived, the maximum stress of key points and important points by FEM are gotten and a certain margin is given, and then determining the warning values and alarm values of every key point, which is set in the software platform. If the stress corresponding points exceed the set threshold value in actual operation, the software platform will send alarm signals to alert the drivers to take necessary measures and inform the responsible person of the crane through 3G network, all these measures aim at accomplishing preventive measures.