Experimental Study on Natural Vibration Characteristics of Double-Strip High-Speed Pantograph Head.

Background: Pantograph-catenary resonance is one of the main causes of the increased vibration amplitudes of the pantograph-catenary system. Experimental identification of the modal characteristics of the complex mechanics of the pantograph can provide basis for determining whether the pantograph-catenary resonance occurs or not and for modeling pantograph dynamics. Objective: The typical service conditions of the pantograph were simulated, and the modal characteristics of pantograph under different service conditions were identified experimentally. Methods: Modal tests of the DSA380 pantograph were conducted at two working heights of pantograph and three boundary constraints of the pantograph head, and the effects of working heights and boundary constraints on the modal parameters of the pantograph head were studied. Results: The natural frequencies and modal shapes of the DSA380 pantograph head in the frequency range of 200 Hz were identified, including coupling vibration modes associated with the bow spring at 30.35 Hz and below, and elastic modes associated with the elastic deformation of the strip at 34.81 Hz and above. Conclusions: The high-order elastic modes of the strip are related to the material and structural parameters, and has almost nothing to do with the working height of the pantograph and the boundary constraints of the pantograph head, thus only one service condition is needed for future testing. However, the low frequency coupled vibration mode is greatly affected by the operating height and boundary constraints, so it is necessary to conduct modal experiments in specific service conditions. [ABSTRACT FROM AUTHOR]