In the absence of measured rail impact data, development programs have typically used a generic criteria as bed-of-the-railcar input for standard draft gear railcars. These rail impact shock criteria are used to support system level design and test efforts, and serve as inputs for prediction of component level shock responses. The criteria were not updated following introduction of cushioned draft gear railcars. A generic value for cushioned railcars contained in NATO Standardization Agreement (STANAG) 4370, Method 403 [1] inadequately describes the shock event in comparison to measured values. An effort was made to develop rail impact shock criteria, based on measured data from a variety of programs. These shock criteria, specified as maximum expected shock response spectrum levels, were developed for various system weight class and axis definition. A method of wavelets and temporal moments was used to improve the similitude of the synthesized waveforms to the measured event time histories.
展开▼
