THEORETIC-PRACTICAL BASIS OF LEVELING OF DEFORMED CARRIER CONSTRUCTIONS BY THERMAL INFLUENCE

Abstract

Purpose. The proposed study is aimed at justifying the expediency of using the thermal leveling method to correct deformations of car metal structures that take place during their manufacture, operation and repair. Methodology. To achieve this purpose a mathematical apparatus was created, which is based on the methods of mathematical design of the experiment. A generalized universal mathematical record of the optimization study of the thermal leveling of car structures has been developed. Modelling of thermal leveling, using the software complex of CAD systems of Solid Works was carried out, as well as an experimental study of the full-size sample of the cantrail in the gondola car. Findings. On the basis of a generalized mathematical record of the optimization study of the thermal leveling of the railcar constructions, mathematical dependencies were created for the thermal leveling of the center sill and the cantrail in the universal gondola cars. These dependences describe the change in the magnitude of the deformation deflection with the corresponding geometric parameters in the heating zones (deflection of the center sill and the profile of the cantrail) depending on the variation of the controlled variables (geometric parameters of the heating spots and temperature). Auxiliary graphs (binary sections) have been constructed for a reasonable choice of the optimal values of the geometric parameters in the heating zones when using thermal leveling of the occurring deformations in the elements of freight cars during their manufacture, repair and operation. Based on the developed finite element models, the efficiency of thermal leveling has been confirmed. The accuracy of the effect obtained in the course of computer simulation is proved experimentally – elimination of the occurred deflection when applying the welding seam in the element of the car structure was noted). Originality. The developed mathematical apparatus and the model created on its basis for the study of the thermal correction in the car structures allow us to justify the selection of the optimal parameters of the marked correction when they are used to eliminate the deformations that occur in the elements of the freight cars. Practical value. Accounting of the obtained results will help to reduce costs in technological processes in the manufacture and repair of freight cars, which is the basis of the rail car fleet of Ukraine.