Interest of Equivalent Damage Methods for Railway Equipment Qualification to Vibrations

Fatigue, induced by vibrations of supporting structures, is one of the major cause of mechanical failures of equipment mounted on vehicles and on machines. Account of vibration excitation should therefore be considered with care when designing new equipment.Equivalent damage methods developed in the 80's for the design of armament equipment are firstly presented in the paper. These methods allow to convert complex time vibration signals representative of in-service vibrations of the supporting structure into simple Gaussian or Sine signals, easy to handle for defining equipment specifications and qualification tests.Then, the interest of these methods for the design of railway equipment is discussed. The IEC 61 373 standard dealing with qualification of railway equipment to train vibrations is assessed in the light of the equivalent damage methods. Some weak points of the standard are pointed out and recommendations for standard updating are given to conclude the paper.