Abstract
This article presents a detailed and comprehensive analysis of the problematic aspects directly related to ensuring the operational reliability and safety of transporting extra-long continuous welded rails (up to 800 m in length) on complex curved sections of the railway network of the Republic of Kazakhstan. An original scientific and methodological approach is presented for the calculated determination of the boundary force impacts formed in critical units and elements of the removable equipment of flatcars when heavy-duty rolling stock moves along track sections with circular geometry of small radius (from 200 to 350 m). A refined nonlinear mathematical model has been developed, allowing for highly reliable accounting of combined spatial deformations in the complex biomechanical and physical "rail – fastening device" system, as well as the assessment of kinematic impacts and distributed forces of dry friction during multi-tier stacking of rails on roller supports. In the ANSYS software computing environment, full-scale 3D modeling of the structure was carried out to perform a series of simulation tests at various operational speed modes (in the range from 5 to 50 km/h). During the mathematical processing of numerical finite element analysis data, the load distribution graphs were programmatically filtered from theoretical mathematical singularities (stress peaks at the points of application of idealized constraints), which made it possible to identify a realistic and physically justified range of working longitudinal loads within 5–20 kN. The results obtained indicate a high degree of convergence between fundamental theoretical calculations and experimental digital data. Based on the study, strict practical recommendations for safe speed limits for rail transportation on small-radius curves are formulated, the implementation of which will minimize the risks of wagon derailment and destruction of fastening racks.