Study of a high-precision, 3D, constant amplitude load spectrum compilation method for design of pantographs

The pantograph, a critical component of the pantograph-catenary system (PCS), operates in harsh environments and is susceptible to crack failures, which pose risks to current collection quality and operational safety. Despite its importance, its service reliability has not been adequately explored. This study presents a novel approach to developing high-precision three-dimensional (3D) load spectra for key pantograph components. Initially, the pantograph-catenary dynamics model is enhanced to accurately capture 3D dynamic loads. Subsequently, multiple methods are employed to fit load spectrum probability densities, with the TOPSIS method identifying the most effective fitting approach. To improve fatigue test efficiency, extrapolated load spectra for varying operational speeds are synthesized and converted into constant amplitude load spectra, which are then combined to generate comprehensive 3D load spectra. Finally, the damage reduction analyses are conducted to confirm the acceptability of the load-induced damage, thereby validating the method’s effectiveness. This innovative approach provides highly precise foundational data, which can be used for structural design and life prediction of pantographs, significantly enhancing their reliability and operational safety.