eva‎luation of track quality indices according to the effect of the wavelength of defects

9/21/2023 12:00:00 AM

Considering the high contribution of railway maintenance costs, it is not cost-effective to carry out maintenance operations without checking the geometry of the track and prioritizing the need for repairs. The assessment of the quality of track geometry has an important effect on the performance of the rail fleet in terms of ride comfort and safety, and their effect is much greater in the high speed range. An irregularity in the geometrical parameters of the track in a diverse range of wavelengths, which may be important and critical up to wavelengths of up to 200 meters. Various track indices have been defined in the railway and are used in the management system of maintenance and repair of railway lines, each of them is not reliable due to limitations or special conditions in some tracks and does not provide acceptable results. In this thesis, an attempt has been made to use a more developed index than other indices and to explain its relationship with other indices. Many and varied methods have been developed so far to analyze, process and interpret the data measured by track recording cars of geometric parameters, which are often reported in the form of quality and track condition assessment indicators. In this research, considering the importance of the range and effective wavelengths in eva‎luating the condition of the line, we intend to investigate the impact of this feature in eva‎luation methods. In this thesis, by calculating the standard deviation index (SD) and using the power spectrum density (PSD) method for the geometric parameter of longitudinal alignment in different parts of the line, an attempt was made to establish a relationship between these two indices and their relationship with the wavelength of the fault caused. The results obtained from the calculations of these two indices showed that the lower the standard deviation values for a part of the line, the PSD curves obtained for the same part are aligned closer to the horizontal axis, which indicates the better quality of the line. Also, from these curves in each part of the line, it is also possible to obtain the wavelength of the created failures and by considering them, the cause of the failure and the best method to correct the line geometry can be suggested.

نگهداري و تعمير , شاخص هندسي خط , انحراف معيار , چگالي طيف توان , پارامتر هندسي

maintenance and repair , geometric parameter , track geometry index , Standard Deviation , Power Spectrum Density

Hengameh azimi

Dr. Saeid Mohammadzadeh