In this article, the considered principles for the development of calculation schemes and the subsequent formation of vibration equations are a special case of classical simulation of motion in space of solid body systems connected in space by kinematic connections. This approach is useful with limited computational capabilities and an assumption of the relatively small body movements inherent in railway crew bodies, and reduces the task of motion research to analysis of fluctuations. Various design schemes of freight car truck, mathematical modeling of systems dynamics, "crew-track" safety of freight car movement and withdrawal under different technical conditions of running parts and track are considered in this work.
Currently, there are many software systems and environments that allow you to simulate and perform fairly complex and voluminous calculations associated with dynamic effects on structural elements of overpasses. The aim of the article is to make an analysis of a reinforced concrete railway overpass as a whole and its elements separately. The article presents the calculated and experimental data of the forms and frequencies of natural vibrations of reinforced concrete railway overpasses under constant loads and the rolling stock off the span. As a result of the analysis of the tests, it was determined that the effect of the rolling stock passing through the reinforced concrete beam spans of 16.5 m and 23.6 m appears with frequency perturbations that are in the range f = 4.41 ÷ 9.52 Hz. These studies can be further used in the design of artificial structures, as well as to identify defects in structural elements of railway bridges.
Summary. Today modern locomotives of KZ4AС, KZ8A, ТE33А series were put into service in the Republic of Kazakhstan. In order to establish safe operating mode of these locomotives the admissible speed on the railway tracks of the Republic of Kazakhstan was determined. The admissible speed of locomotives was determined on the basis of analysis on the results of dynamic and railroad tests and calculations for stress of railway construction. ОПРЕДЕЛЕНИЕ ДОПУСТИМОЙ СКОРОСТИ ДВИЖЕНИЯ ЛОКОМОТИВОВ ПО ЖЕЛЕЗНОДОРОЖНЫМ ПУТЯМ РЕСПУБЛИКИ КАЗАХСТАНАннотация. В настоящее время в Республике Казахстан введены в эксплуатацию современные локомотивы серий KZ4AС, KZ8A, ТЭ33А. Для установления безопасных режимов эксплуатации этих локомотивов определены допустимые скорости движения по железнодорожным путям Республики Казахстан. Допустимые скорости движения локомотивов определены на основе анализа результатов динамических и путевых испытаний, а также расчетов напряжений в конструкции железнодорожного пути.
Theoretical identification methods for complex industrial control objects give very cumbersome and complex mathematical relations, the use of which for practical purposes is not constructive. In this regard, methods for obtaining mathematical models based on experimental data have now become the main focus of identification theory. In this paper is described the method of identification of industrial control objects developed according to their acceleration characteristics. The structure of the object under study is determined by the type of amplitude-phase frequency response and dynamic parameters are determined by experimental data. The high adequacy of the method is confirmed by similar studies on known (reference) models. The scientific novelty of the work consists in development of a new method for identifying complex industrial control objects by their acceleration characteristics.
Need of use of mobile measuring computer systems when performing diagnostics of bridges is shown and also the analysis of amplitude-phase-frequency characteristics frame reinforced concrete and metal flying structures of railway bridges is provided at the movement of the train. This in turn allows to estimate conditions of span structures by width of ranges in points of half energy of spectral curve in the area of resonances. Assessment of technical condition and diagnostics of supported artificial structures is carried out according to dynamic parameters. According to this method frequency of natural oscillations is determined from peak values of averaged spectral densities of reduced power. Comparing width of the received ranges to ranges of the new (intact) flying structures it is possible to estimate degree of wear and a damage rate of elements of designs. Based on the results of the calculations, it has been confirmed that the inclusion of elements of the bridge web and the upper structure of the track in the joint work with the main bearing structures increases the accuracy of solving the problem of determining natural frequencies.
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