Investigation of the Influence of a Cavity Type Defect on the Frequencies of the Natural Rail Oscillations by the Radar Method

Abstract

Currently, the problem of non-destructive testing of rail lashes or rolling stock is quite acute, as the demands of both speed characteristics and vehicle safety increase every year. Thus, the purpose of this study was to determine the possibility of recording frequencies of natural oscillations by the radar method for rail lashes and the influence of the dimensions of the cavity-type defect. For this purpose, a laboratory bench was created with a standard rail, the length of 1.19 m of the P-65 brand, in which free oscillations were excited using a shock impulse load. Measurements of natural oscillation frequencies of the rail were recorded on a 24-bit ADC and a specialized accelerometer ZETLAB BC110. To register the oscillations, a Doppler radar with a frequency of 10 GHz was used, which was installed at the focus of a parabolic mirror offset antenna with a 1.6-meter diameter. It was found that a “field” defect shifts the frequency mode of oscillation 750 Hz upwards. It is shown that the hole in the rail neck with a diameter of 10 mm makes a change in the frequency of about 14 Hz

Comparison of theoretical modeling of natural frequencies of a pipe section with data obtained empirically

“…A set of a large amount of statistical data will make it possible to build various pipeline models taking into account the development of stressed sections, based on sensor data, which in turn makes it possible to predict the course of the defect formation process. Vibrodiagnostics methods are described in works [26,27].…”