Theoretical and Experimental Research on Switching Optimization of No. 9 Single Turnout with 60-kg/m Rails

Based on the necessity of optimizing the structure of No. 9 single turnouts of 60-kg/m rails, we addressed the issues associated with existing turnout switching design methods. Based on finite element analysis, we established a refined calculation model for turnout switching. The model can determine the plane alignment of a switch rail separated from the stock rail based on the actual force acting upon the switch rail. The obtained plane alignment is consistent with the actual situation and is thus reliable. Based on the established turnout switching model, the minimum flangeway width and dynamics between the strokes of the first and second traction points under different conditions were analyzed by numerical simulations. Accordingly, we propose an optimized scheme that takes 160 mm and 85 mm as the stroke value for the first and second traction points, respectively. The scheme helps to meet the requirements for minimum flangeway width while making the deformation of the switch rail more even and therefore minimizing the traction power. Based on the proposed design, trial production and laying of the new No. 9 single turnout with a 60-kg/m rail was conducted, and a switching test was performed. The switching forces at the first and second traction points of the new No. 9 turnout were approximately 1200 and 2000 N, respectively, which were higher than those of existing No. 9 turnouts with 60-kg/m steel rails. Besides, the minimum flangeway width satisfies the requirement for safe vehicle passage with a safety margin of 3–5 mm. The test results proved the effectiveness of the proposed turnout switching design method and parameter optimization scheme.

Об использовании параметров структурного шума при контроле поверхностными акустическими волнами Рэлея стали 20ГЛ в процессе упругопластического деформирования

The relevance of the work is due to the need to create methods for determining the stress-strain state of acoustically anisotropic structural materials in the composition of technical objects operated in Arctic conditions. The features of using the acoustoelasticity phenomenon for materials with different values of acoustoelastic coefficients, acoustic anisotropy, and temperature dependence coefficients of acoustic parameters appearing in the calculation algorithms are analyzed. It is established that the existing approaches to accounting for temperature effects in a number of important cases lead to noticeable errors in determining mechanical stresses in the material of critical technical objects. At the same time, taking into account the temperature corrections is necessary for both biaxial (flat) and uniaxial stress states. The presence of anisotropy of the thermoacoustic coefficients of transverse waves for materials with anisotropy is experimentally shown. Refined calculation formulas for determining the one - and two-axis stress state of an anisotropic material, taking into account the anisotropy of the thermoacoustic coefficients of transverse waves, are proposed.

Refined calculation of low-frequency filters on direct current locomotives with induction traction drive

The paper proposes a refined calculation of parameters of low-frequency filters used in direct current locomotives with induction drive. It also provides requirements to setting of filter’s coefficients and equations for constructing frequency characteristics. As a result, the author gives recommendations on improving transient processes in power circuits by optimization of parameters of low-frequency filters.

REFINING THE CALCULATION OF THE CAR TRACTION POWER

Introduction. Traction power of the car is used to determine its traction-speed properties. The purpose of the paper is the calculation refinement of the car traction power.Materials and methods. The authors used the methodology of the refined calculation of the car traction power.Results. The authors carried out the comparative analysis of the refined and traditional methods for calculating traction power. As a result, the authors obtained the refined equation for calculating the traction power, taking into account the elastic modulus, the width of the contact track, the free radius of the wheel, the deflection of the tire and the tangential friction forces in the contact zone. The largest discrepancy between the curve of the vehicle’s traction power calculated by the updated methodology and the curve of the vehicle’s traction power calculated by the traditional method was 26.8%.Discussion and conclusions. The results of the research are useful to specialists of automobile and transport enterprises and masters of universities to compare the traction and speed properties of the various car types.