Detection, characterisation and synthesis of transient track irregularities for design load calculation of railway vehicle bogies
Representative track irregularities are required for multibody simulation based design load calculation. An algorithm for the detection and characterization of short, transient track irregularities is presented. The algorithm is based on the continuous wavelet transform and uses the second order derivative of the track irregularities. Furthermore, instructions for the generation of synthetic transients are provided. The detection algorithm is applied to measured track irregularities and the identified transients are used to generate synthetic track irregularities. Multibody simulations are conducted using the measured track irregularities as well as some irregularities generated from power spectral densities with and without adding the detected transients. Comparisons of the resulting loads of a primary vertical damper, sensitive to short track irregularities, reveal good and much better qualitative and quantitative agreement when transients are included.