基于光纤光栅传感器的动车组结构累积损伤预测系统设计

Design of cumulative damage prediction system for EMU based on fiber Bragg grating sensor

为降低动车组维护成本及减少电磁干扰,采用光纤光栅技术对动车组结构疲劳寿命进行预测。开发了针对动车组焊接结构的动应力数据采集和累积损伤预测系统,在动车组焊缝部位布置光纤光栅传感器,采用光纤光栅动态解调仪SM130进行光波信号解调,工控机进行采集控制与数据存储。基于LabVIEW软件开发数据采集与处理、雨流计数、S-N曲线编制、损伤及寿命计算程序。利用IIW国际焊接学会标准中的焊接接头S-N曲线数据,基于Miner累积损伤原理进行疲劳寿命预测。采用本系统对某高速动车组设备舱支架焊缝进行动应力监测及损伤预测,损伤预测结果为3.29×10^-6,可运用里程3.3×10^7km,满足设计寿命1200万公里的要求。本系统可用于强电磁干扰环境下焊接结构的疲劳损伤监测。

In order to reduce the maintenance cost of EMU and the electromagnetic interference,the FBG technology is applied to predict the fatigue life of the EMU.The dynamic stress data acquisition and cumulative damage prediction system for the welding structure of EMU are developed.The FBG sensor is arranged on the welding seam of EMU.The optical fiber signal demodulator SM130 is used to demodulate the light signal.The IPC controls the data collection and control storage.Based on LabVIEW software develops data acquisition and processing,rain flow count,S-N curve preparation,damage and life calculation program.By IIW S-N curve data for welded joints in the International Welding Society standard,the fatigue life prediction based on Miner cumulative damage theory.A high-speed EMU equipment cabin bracket weld is monitored and dynamic stress damage prediction by this system.The damage prediction is 3.29×10-6,the available mileage is 3.3×107 km,they meet the design life of 12 million kilometers of requirements.The system can be used for fatigue damage monitoring of welded structures under strong electromagnetic interference environment.