Fatigue life enhancement of catenary droppers for high-speed railways based on arrangement optimization

•We firstly combine 3D FE pantograph-catenary (PC) dynamic model with fatigue analysis to estimate the fatigue life of catenary droppers.•We carefully consider the interactions within PC and dropper’s vibration.•Machine learning technique can be used to seek the optimum catenary structure.•Vulnerable dropper fatigue life would be increased from 0.96 × 106 to 4.36 × 106 by optimizing the catenary structure. While high-speed trains rely on the pantograph-catenary system (PCS) to collect electric energy, the catenary droppers constantly work as the key component of hanging contact wire, ensuring the stability of highspeed current-carrying slide. During train operation, dropper suffers from high-frequency bending and stretching due to the repeated interaction within PCS, which would inevitably accelerate the process of fatigue fracture and potentially threat the operation safety. Herein we propose a strategy of life prolong method for the catenary droppers, based on the fatigue analysis and machine learning technique. Firstly, a three-dimensional finite element (FE) model considering the spatial distribution of dropper has been constructed to simulate the interaction within the PCS. Then, the FE model was used to carry out parameterization numerical calculations combined with machine learning techniques, to seek the potential optimal scheme of the dropper arrangement. Subsequently, the performance of benchmark and optimum structure were detailly compared and analyzed in the static characteristics and dynamic response. Finally, the fatigue life was estimated according to the stress analysis results of the dropper. The results indicated that the method proposed in this paper can effectively extend the fatigue life of droppers.