Evaluation of the influence of pantograph cracks on contact forces in the interaction between pantograph and catenary

Pantograph-catenary (P-C) systems operating under cracks would induce potential risks to railways. Previous relevant research efforts lack consideration of the dynamic characteristics of P-C systems under crack damages. A rigid-flexible P-C coupling model with pantograph cracks for a metro line is developed in this study. The evolution law of P-C contact forces under the condition of cracked propagation is described, and the influence of speed, uplift force, span length, and pullout value arrangement on P-C contact force and the sensitivity of crack influence are explored. Results show that the dispersion of contact force values decreases continuously upon the existence and expansion of cracks on the pantograph. Proper selection of operating conditions is advised because of the sensitivity differences of the five influencing factors indicates. Metro trains should not be operated at 100 km/h for the rail section with an 8 m-span catenary, and further inspections on the pantograph should be scheduled for trains operating over 100 km/h. The uplift force should be adjusted to the 90-100 N range. The 8 m span length is suggested in a metro catenary, and the splayed arrangement of pullout value is recommended as a priority when the situation allows.