Yosifovich R. Scientific substantiation and practical decision of the problem of operating resource of rails increase at Kiev's underground

Dissertation is devoted a scientific substantiation and practical decision of the problem of operating resource of rails increase at Kiev's underground by the additional use of remaining resource of rails that have defects of contact fatigue character on rails head surface, that grounded experimentally and theoretical by researches. The methods of mathematical statistics was established graphic and analytical dependence of exception of rails from exploitation after reason of appearance contact fatigue defects of kind 11.2-11.1 on rail's head surface, from tonnage that the rails fulfilled. The results of statistical researches of the rails, that have defects withdrawn from exploitation, depending from fulfilled tonnage, allowed to make prognosis the terms of service of underground rails depending on defects accumulating. By theoretical calculations, with the use of different calculation methods, in that number the method of eventual elements (MKE), was established tensely deformed the state of rails as R50 in the area of contact interaction of wheel and rail on rail's of head surface for the operating terms of Kiev's underground. The stand experimental tests of pre-production models of defected rails on multicycles endurance were made with the purpose of determination of them remaining resource, and also break tests were made with the action of the maximum vertical loading. Results of the fulfilled tests allowed to define a remaining resource for rails R50 and R65, that have defects of contact fatigue character on rail head surface for operating terms of Kiev's underground. New norms are increased in relation to existing accordingly on 33,3% and 16,7%. for rails R50 and R65