Study of the stress state of the sleeper base and sleepers of rail track with accounting variable conditions of their resting

2020 ◽  
pp. 200-217
Author(s):  
V.V. Hovorukha ◽  
◽  
A.V. Hovorukha ◽  
V.K. Kizilov ◽  
T.P. Sobko ◽  
...  
Keyword(s):  
Stress State ◽  
Mutual Influence ◽  
Shear Zones ◽  
Shear Resistance ◽  
Middle Part ◽  
Shear Stresses ◽  
Railway Transport ◽  
Base Stability ◽  
Resistance Forces

The live problem of the stress state of the sleeper base and rail sleepers is considered in the article with taking into account specific normal and specific shear stresses under variable conditions of the sleepers resting on the base. The methodology is aimed at the determination of the mutual influence of normal (compressive) and tangential (shear) specific stresses on formation of stability due to the displacement of individual parts of the base. Stability zones and shear zones of the sleeper base parts are also determined by the authors at different conditions of the sleeper resting on the base. Further, zones with insecure position of the base under the sleepers are found when they and their under-rail parts continuously rest on the base. It is stated that insecure position of the base is formed when specific shear stresses excess specific stresses of shear resistance, which consists of specific friction and specific cohesion between the parts in the base. It is also established that loss of stability of the ballast particles causes their displacement in the direction of the action of specific shear stresses. In these zones, density and rigidity of the sleeper base decreases leading to a gradual redistribution of reactive resistance of the base along the sleeper, and, depending on this redistribution, a change in the bending moments acting on the sleeper occurs. It is found that when the sleepers rest only by their under-rail parts, shear stresses and forces, as well as stresses and shear resistance forces under the middle part of the sleepers are distributed in such a way that shear forces exceed resistance forces up to the depth of 60 cm from the sleepers sole. This phenomenon leads to the displacement of ballast particles under the middle part of the sleeper, consolidation of the ballast and resting of the sleepers by their middle part with possible cracks formation. In the end sections of the sleepers, there is also a loss of ballast stability. Recommendations for improving stability indicators of the sleeper base and strength of the sleepers are given. The obtained results of the study can be used for the mine, industrial and railway transport.

scholarly journals Determination of the Stress State of a Piecewise Homogeneous Elastic Body with a Row of Cracks on an Interface Surface Subject to Antiplane Strains with Inclusions at the Tips

2015 ◽  
Vol 2015 ◽  
pp. 1-22 ◽  
Author(s):  
Ali Golsoorat Pahlaviani ◽  
Suren Mkhitaryan
Keyword(s):  
Stress State ◽  
Elastic Body ◽  
Linear Equations ◽  
The Body ◽  
Shear Stresses ◽  
Interface Surface ◽  
Special Cases ◽  
Crack Problems ◽  
Fourier Sine Series

The stress state of a bimaterial elastic body that has a row of cracks on an interface surface is considered. It is subjected to antiplane deformations by uniformly distributed shear forces acting on the horizontal sides of the body. The governing equations of the problem, the stress intensity factors, the deformation of the crack edges, and the shear stresses are derived. The solution of the problem via the Fourier sine series is reduced to the determination of a singular integral equation (SIE) and consequently to a system of linear equations. In the end, the problem is solved in special cases with inclusions. The results of this paper and the previously published results show that the used approach based on the Gauss-Chebyshev quadrature method can be considered as a generalized procedure to solve the collinear crack problems in mode I, II, or III loadings.

Photoelastic Determination of Interfacial Shear Stresses in Model Composites

2007 ◽  
Vol 334-335 ◽  
pp. 289-292 ◽  
Author(s):  
F.M. Zhao ◽  
Z. Liu ◽  
F.R. Jones
Keyword(s):  
Glass Fibre ◽  
Mechanical Response ◽  
Interfacial Shear Stress ◽  
Stress Transfer ◽  
Interfacial Shear ◽  
Shear Stresses ◽  
Contour Maps ◽  
Phase Stepping ◽  
Fibre Matrix

Phase-stepping photoelasticity has been used to study the fragmentation of an E-glass fibre in epoxy resin and examine quantitatively the effect of a transverse matrix crack on the stress transfer at an interphase. Unsized glass fibre was coated by plasma polymerisation with a crosslinked conformal film of 90% acrylic acid and 10% 1,7-octadiene. The micro-mechanical response at the fibre-matrix interphase and in the adjacent matrix has been described in detail using contour maps of fringe order. From these, the interfacial shear stress profiles at fibre-break have been calculated.

Graphical-Numerical Solution of Problems of Saint-Venant Torsion and Bending

1953 ◽  
Vol 20 (3) ◽  
pp. 321-326
Author(s):  
B. A. Boley
Keyword(s):  
Cross Section ◽  
Stress Function ◽  
Arbitrary Cross Section ◽  
Successive Approximations ◽  
Shear Stresses ◽  
Shearing Stress ◽  
First Approximation ◽  
Difference Form ◽  
Bending Of Beams

Abstract A simple successive-approximations procedure for the solution of the problems of Saint-Venant torsion and bending of beams of arbitrary cross section is presented. The shear stresses in a cross section of the beam are first calculated from the formulas valid for thin-walled sections, on the basis of an assumed set of lines of shearing stress. From these a first approximation to the stress function of either the torsion or the bending problem is found. The second approximation to the stress function is then obtained from the governing equation of the problem, expressed in finite-difference form; this in turn allows the determination of an improved set of lines of shearing stress, and hence of the shearing stress itself. The procedure can be repeated until the results of two successive steps are sufficiently close. Applications are presented for a beam cross section for which the exact solutions are known, and it is shown that no further difficulties arise in applications to more complicated shapes.

scholarly journals THE ANALYTICAL DETERMINATION OF THE PARAMETERS OF THE WELL WHILE ELIMINATING UNEQUAL SETTLEMENT OF FOUNDATIONS METHOD OF DRILLING-OUT OF THE SOIL

2020 ◽  
Vol 11 (2) ◽  
pp. 40-48
Author(s):  
Y. A Pronosin ◽  
M. D Kaygorodov ◽  
A. M Karaulov
Keyword(s):  
Stress State ◽  
Clay Soil ◽  
Reduction Process ◽  
Soil Characteristics ◽  
Shallow Foundations ◽  
Analytical Determination ◽  
Advantages And Disadvantages ◽  
Drilling Parameters ◽  
Soil Destruction

Existing approaches which allow to reduce the settlement unevenness of buildings and structures have their own advantages and disadvantages. One of the promising methods for reducing shallow foundations the settlement unevenness, which are based on soft dust and clay soil, is the building or its part lowering. The effect is achieved by drilling vertical wellbores in the immediate proximity to the existing foundation from the side of the least settlement. At different times, domestic and foreign scientists were engaged in to the methods of horizontal and inclined drilling of wellbores, an important issue, when applying this technology, is the determination of drilling parameters, the influence of soil characteristics and the stress state of the soil around the well, on the roll reduction process. The article considers the influence of the soil strength characteristics on the stress state of the soil which are surrounding the wellbore, and the effect of the drilled wellbore radius on the formation of the critical state regions. The analytical solution is based on the use of the well-known relationship for determining the stress state around the well during pressiometric tests. From this ratio, tangential and radial stresses are determined, which are then checked according to the condition of the law of strength, thereby forming a picture of the stress state around the well. According to the presented methodology, the stress state of the soil around the wells was calculated, which allows calculating the zones of soil destruction and thereby determining the parameters of the wells and the geometry of their location depending on the goals, when regulating the sediment of slab foundations.

scholarly journals Modeling of diversification of foreign economic interactions

2018 ◽  
Vol 16 (1) ◽  
pp. 155-165
Author(s):  
Ihor Hroznyi ◽  
Oleh Kuzmak ◽  
Olena Kuzmak ◽  
Olha Rusinova
Keyword(s):  
Dynamic System ◽  
Simulation Model ◽  
Mutual Influence ◽  
Model Development ◽  
Complex Dynamic ◽  
Complex Dynamic System ◽  
World Markets ◽  
Economic Interactions ◽  
Simulation Package

The article developed a basic simulation model of diversification of foreign economic interactions, which makes it possible to assess the mutual influence of key economic indicators and their reaction to changes in the equilibrium in world markets. The peculiarity of the developed model of diversification of foreign economic interactions is its functioning as a complex dynamic system in which many factors are interrelated, and the connections are dynamic. This makes it possible to calculate a simulation model that takes into account hidden and subtle connections. While modeling foreign economic interactions and evaluating the influence of various regulators on them, in addition to the stage of model development itself, mandatory parameterization of this model is proposed, that is, the determination of specific types of dependence between the factors included in the model and the parameters of these dependencies. The implementation of this model can be carried out in any simulation package.

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