Scientific novelty of the work:
- Based on the method of generalized solutions, effective solutions were obtained for the problem of bending strips adjacent to a linearly deformable anisotropic base;
- the stress-strain state of three uninsulated endless or semi-infinite tapes on a linearly deformable anisotropic base was studied;
- the stress-strain state of three non-isolated strips on a linearly deformable anisotropic base was studied;
- Analysis of the influence of soil anisotropy, belt dimensions, load characteristics and belt fastening conditions on the distribution of deformations and forces in uninsulated belts.
The reliability of the results of the dissertation is ensured by the rigidity of the conclusions and mathematical methods for solving the problems under consideration, in a number of special cases by comparison with the results of known solutions.
The practical significance of the work. Analytical solutions are designed for bending of uninsulated strips and rectangular slabs on an anisotropic base, linearly deformed under the action of free external loads. Calculations and results are used in the practice of designing industrial buildings, airfields and sidewalks, etc. floor slabs and slats are designed using automated calculation and design programs that allow you to perform calculations.
Publications on this work. 1 article on the topic of the dissertation has been published.
The following is submitted for defense:
1. Solution of the problem of bending one and three non-isolated endless tapes with free and hinged edges lying on a linearly deformable base.
2. Solve the problem of bending one and three non-isolated semi-infinite strips with free and hinged edges lying on a linearly deformable base.
4. To study the influence of the width of uninsulated endless and semi-infinite strips on the distribution of strains and forces in them.
5. To study the influence of the anisotropy of a linearly deformable base on the distribution of strains and forces in the strips.
Modern methods for calculating the foundations of structures and structures on an elastic foundation are mainly based on the analytical description of mechanical phenomena. To do this, for example, draw a diagram of the structure and properties of structures, external influences, operating conditions, etc. Differential and integral equations are used based on the choice of a system of assumptions or hypotheses. The validity of these hypotheses and the compliance of the chosen design scheme with the real nature of the structures are tested in practice. Thus, the results of experimental studies are used in the selected calculation scheme, and hence in the corresponding equations.
The practical application of such models is associated with the use of simplified schemes and numerical calculation methods and computers, which radically eliminates the need for excessive idealization of the properties of soils and rocks.
Figure 2.1.1. Calculation scheme of an endless belt lying on an elastic foundation and loaded with an arbitrary load
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Fig.3.3.1. Calculation scheme of three adjacent semi-infinite belts loaded on an elastic base and arbitrary load
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The method of general solutions for given bands was used to calculate infinite bands. As a result of the research work with the supervisor, the main method for calculating the fields was developed using the found literature.
The practical application of such models is associated with the use of simplified schemes and numerical calculation methods and computers, which radically eliminates the need for excessive idealization of the properties of soils and rocks.
Thus, to calculate the structure and foundation of structures on an elastic anisotropic foundation, it is necessary to use universal numerical methods in connection with the rapid development of analytical and computer technology within the allowable limits of application.
A calculation model has been developed that takes into account the boundary boundaries of the joints of the strips.
To improve the convergence of incorrect integrals in the obtained formulas, the well-known method /40/ was also used, in which the original integral is expressed as the sum of two terms. The first term corresponds to the Winkler model, and the second is an additional, double integral that accumulates faster than the original one.
The results of calculations and studies were entered using the Plate 5.0 program.
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Figure 2.1.2. Deflection diagrams of an infinite plate loaded with a concentrated force P = 1
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Figure 2.1.3. Diagrams of bending moments in an infinite plate lying together
horizontal isotropic base and horizontal isotropic half-space
concentrated force at the beginning P = 1
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Figure 2.1.2. Graphs of bending moments on an infinite plate loaded with a load q = 100, uniformly distributed on a platform of size 0.1 x 0.1, located at the point (x0, y0).
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Also shown is the basic method for calculating bars in the form of hinges and loose edges. As is known, when the load is unloaded near the edge of the strip, this can be taken into account by the design scheme of the semi-infinite strip. This chapter considers the problem of bending one and three neighboring semi-infinite strips on combined anisotropic and isotropic bases.
Stress values σz in the half-space under the action of a concentrated load on the strip
Number of nodes according to the scheme
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1005
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1015
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1025
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1035
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1045
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1055
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1065
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1075
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1085
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1095
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Depth at: h, m
h=H-y
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0,05
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0,276
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0,760
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1,453
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2,356
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3,467
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4,787
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6,316
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8,053
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10
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-σz MPA analyt.
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0,99
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0,49
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0,08
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0,03
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0,02
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0,01
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0,01
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0,00
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0,00
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0,00
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-σz MPA FEM
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0,99
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0,50
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0,09
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0,04
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0,03
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0,02
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0,01
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0,00
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0,00
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0,00
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Figure 3.3.2. The concentric force P = l acts on three semi-infinitely empty
deviation charts in bars
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Figure 3.3.3. Plots of bending moments Mx(x,y) in three semi-infinitely empty bands with shapes at P = 1.
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Figure 3.3.4. Diagrams Mx(x,y) of bending moments in three semi-infinitely free belts are loaded in parts at P = 1.
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Figure 3.3.5. Diagrams of deflection in three semi-infinite hanging belts loaded with concentration P = 1
Figure 3.3.6. Mu(x,y) Patterns with slices along three semi-infinite hinged bands at P = 1
Figure 3.3.8. (x0=0, y0=0) deflection diagrams in three free-lying semi-infinite bands with uniformly distributed intense loads around the point 0.1 x 0.1 at q = 100.
However, if the previously taken strips are also loaded, the negative bending moments in the strips will be lost. For example, when a load of 0.2 P is applied at a point with coordinates, the negative values of the moments in neighboring bars are lost. In this case, it can be assumed that the real weight of the plates does not allow the plates to break, i.e. Apparently, the two-way connection between the plate and the base can always be predicted.
Figures 3.3.5 - 3.3.7 show diagrams of deviations from the action of a concentrated force P = l with hinged ribs. It can be seen from them that the nature of the boundary conditions leads to the loss of jumps along the lines and on the deviation diagrams (Fig. 3.3.7).
Figures 3.3.8 - 3.3.10 show diagrams of deviations and internal forces from a uniformly distributed load of size 0.1 x 0.1 and intensity q = 100 used at the origin.
Thus, an analytical solution was obtained for three uninsulated semi-infinite tapes with free and hinged edges lying on a linearly deformable base. Quantitative studies have been carried out, methods and schemes for calculating three semi-infinite bands on a combined anisotropic basis have been developed.
The dissertation article was written by:
2. Otelbay M.D. Calculation of three non-isolated bands on a transversally elastic foundation under the action of a concentrated force // Scientific horizons. - 2022. - No. 3 (55). - 179-184 p.
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