STUDY ON PARAMETRIC EXCITATION RESPONSE OF PERIODICALLY SUPPORTED TRACK DUE TO A HARMONIC MOVING LOAD

摘要

The parametric excitation response of the periodically supported track due to the harmonic moving load was studied through an analytical solution based on the periodic-infinite structure theory.Through analysis,the following conclusions can be obtained: (1) Under a harmonic moving load with frequencyfl,the parametric excitation response induced by the discrete support of rail won't have a significant influence on response spectrum in the frequency band around the load frequencyfl.But it will have a significant contribution in narrow frequency bands around frequency fl ± nv/L (n is an integer and n ≠ 0); (2) The influences of parametric excitation response on the rail total vibration responses of different points in a span of the periodically supported track are nearly the same.