Nauka ta progres transportu (Sep 2015)
THE RATIONALE FOR EXTENDING THE SERVICES OF PASSENGER CARS WITH POCKETS OF CORROSION IN THE CENTER SILL
Abstract
Purpose. The scientific work supposed: 1) the search of accounting ways of the local corrosion damages influence to the car design, that were expired the appointed time, for the purpose of renewal; 2) experimental verification of conformity of material construction requirements of the normative documentation and justification for extending the services of passenger cars with pockets of corrosion after 30 years of operation; 3) the conformity assessment of residual life of the structure of car bodies operating pressures in the next 5 years of use. Methodology. The developed algorithm of technical diagnostics of cars with pockets of corrosion of the center sill contains several stages. First, a survey of technical condition of structures is conducted by a visual-optical method and nondestructive control methods, and the degree of damage is determined. In the next phase the experimental verification of conformity of the structure and mechanical properties of the center sill of the car with the pockets of corrosion to regulatory requirements are executed. Next, the study of strength of the supporting structures of car bodies on the basis of experimental static and impact tests of strength is executed. Finally, the endurance tests are conducted on the effect of the longitudinal forces and the evaluation and prediction of compliance resource car bodies for the next period are executed. Findings. The actual work is completed by obtaining the experimental data on the feasibility of extending the service life of passenger cars as from the point of view of an operating time of load-bearing elements of the car body to the resource, and from the point of view of chemical composition, structure and mechanical properties of the center sill with pockets of corrosion. The presence of local corrosion damages of the center sill of the presented size is not a threat to the structural strength and safety. Originality. The authors conducted a comprehensive study to validate the service life of passenger cars both on the part of the operating time of the car bodies elements on impact toughness and the evaluation the mechanical properties of the metal from which the elements of the car are produced. For the first time the possibility of further operation of cars with corrosion damages in the center sill is grounded. Practical value. The obtained results allow without the additional activities to extend the service life of passenger cars with pockets of corrosion in the center sill.
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