ABOUT OF THE METHOD OF DECREASE RAIL TRANSPORT IMPACT NOISE IN LOW FREQUENCY RANGE

Abstract

The method of decrease impact noise between of wheel pairs rail transport and rail joints being main sources of noise is analyzed. The spectrum of such noise reaches a maximum in an octave strip of 31,5 Hz and sharply decreases in a strip of 1 kHz. The practical implementation dipole effect can be received by formation a pair of the knock impulse sources when the direction of acoustical axes is along the railway under small angle. The compensatory effect when one rail joint for example right moves according left joint in other rail on the distance d having half of wave length of the basic low-frequency range of shock impulses is reached. The system of standing waves in the interval d by an antiphase pair of sources with coherent components in the basic frequency 31,5 Hz and odd harmonics is formed. The new additional effect to noise reduction by replacement the rectangular rail joint edges on the oblique-angled rail joints having 45 degree edge angle is carried out.