No abstract

Objective: Development of proposals for modernization of old-type RU1 type axles for their further use. Methods: Structural analysis method was applied. Results: Proposals on further use of old-type RU1 type axles and expanding their operating life. Practical importance: The proposed modernization would permit expanding the use of old-type RU1 axles after modernization with new face bearing retention and reducing the demand for new axles which would contribute to reduction of axle defi cit in overall repair of wheel pairs.

Objective: Development of a methodology for determining the design life of solid-rolled wheels of railway rolling stock, based on the requirements of the current regulatory documentation. Methods: Methods of the theories of probability, reliability, elasticity and numerical solution of partial differential equations (finite element method) are applied. Results: A methodology for calculating the design life using the criteria of TR CU 001/2011, TR CU 002/2011 and GOST 33783–2016. Practical importance: The developed method will make it possible to exclude the presence of wheels with a significant service life on the railway infrastructure which do not provide the required level of reliability, which, in turn, can lead to sudden destruction of wheels under the cars.

Objective: To assess the effect of the dimensions and tolerances of three-piece bogies of freight cars with a maximum static axle load of 23,5 tf when they are released from scheduled repair on the wheel flange wear in operation. Methods: For this purpose, drawing on a review and analysis of the literature in the field of wheel-rail system wear and the current requirements of guidelines for the repair of freight cars and their parts, design cases were formed to simulate a railway crew movement along a track of various designs with operating speeds, and the processes of wheel flange wear were studied using simulation computer modeling in the environment of the “Universal Mechanism” software package. Results: The parameters of freight car bogies which have the greatest impact on wheel wear have been determined. The quantitative values of the indicators of wheel wear for various cases of crew movement have been determined. The ways of reducing the wear of car wheels in operation by changing the dimensions and tolerances of bogies when they are released from scheduled types of repair are shown. Practical importance: The obtained results of the work commissioned by JSC “First Freight Company”are currently used to formulate requirements for the dimensions and tolerances of bogies when they are released from repair in order to establish the optimal parameters that would help to reduce the wheel flange wear in operation. In addition, they can be used in the developing new designs of freight car bogies.

При моделировании динамического поведения бетонных и железобетонных сооружений под действием аварийных нагрузок напряже­ния в отдельных элементах конструкции зачастую достигают значений, существенно превышающих пределы прочности бетона. Для корректного прогнозирования последствий таких воздействий на сооружение необходимо в расчетах учитывать эффекты, свя­занные с нелинейным поведением бетона, вызванным его разрушением. В статье представлен пример использования упругопластиче­ской модели бетона при решении задачи о воздействии взрыва на железобетонную плиту.