Study on reliability of metro vehicle doors based on exponential distribution and RAMS

For the purpose of preventing and reducing metro door failures, an exponential distribution function was used to analyze the door failure time intervals based on statistical data of three-year door failures on Shanghai metro line 13. Combined with the reliability theory in RAMS, the reliability of doors in three years was analyzed, and a method to determine the preventive maintenance cycle of doors with the comprehensive reliability of train doors as the goal was put forward. The results show that the three-year door failure time interval obeys exponential distribution function and door failure rate determines the reliability of the door. The smaller the door failure rate, the higher the reliability of the door and the longer the working time of the door; otherwise the shorter the working time of the door. It was suggested that in addition to the daily necessary maintenance of train doors, dynamic preventive maintenance cycle can be obtained according to the annual door failure data, so that the preventive maintenance cycle can be set in a specific year, thus improving the reliability of train doors. The method can provide a reference for improving the reliability of the door.