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There is known a method of receiving twisted threads by addition of several threads of raw silk, preliminary reporting the right twist, then these threads are connected and reported into the left twist. Raw materials for production of silk fabrics with crepe effect re prepared in such method [3]. Deficiency for this method is that upon two phase method of prepared twisted threads — produced silk fabrics to some extent are confirmed to crease retention at tip of products. A new way for receiving twisted silk thread from raw silk, consisting in twisting torsion, differs with that fact that for receiving a thread of linear density 18-26 tex there is used raw silk of linear density of 2,33 and 3,23 tex by addition of two threads and torsion 800 kr/m in the left direction then additions of two threads and torsion 750-tw/m, in the right direction and the third time addition of both of these threads and torsion 700-tw/m in the left direction, then steam chamber is counterbalanced a three-phase twist of threads. On novelty of a method there is acquired IAP patent No. 20130325.
For receiving a new sample of silk fabric with linen weave on surface in the form of effect of a cell there were exposed threads to multi-colored dyeing.
In the result there is worked out dress and costume fabric with formation of effect of a multi-colored cell due to use of colored new twisted threads of increased linear density as on a basis and on weft, providing its high durability and crease-resistance, sample of fabric is given in fig. 2. (there is acquired SAP patent No. 01254)
Figure 2. A new sample of silk fabric with cell effect
Conclusions:
1. With analytical research it is established that classical range of crepe silk fabrics generally with linen weave, are developed from raw silk from linear density of 2,33 tex in several additions and by giving various twist to threads.
2. There is worked out a way of development of new range for twisted silk thread and there is made fabric sample on surface in the form of multi-colored effect of a cell. (There is acquired IAP patents No. 20130325 and SAP No. 01254)
References:
1. Михайлов Е. Н. Шелководство. - М. - 1950. - 496 с.
2. Рубинов Э. Б. Технология шелка. - М. - 1981. - 393 с.
3. Усенко В. А. Шелкокручение - М. - 1983. - 248 с.
4. Справочник. Переработка химических волокон и натурального шелка. Часть III. Ткачество и ассортимент. - М. - 1970. -445 с. (Под общей редакцией к. т.н. М. Д. Талызина)
5. URL: http: www shweinoedelo.ru. assortiment - tkanei.
6. Алимова Х. А., Усенко В. А. Ипакни эшиш. - Тошкент. Шарк; нашриёти. - 2001. - Б. 249.
7. Арипджанова Д. У Создание комплексной технологии производства женской одежды из шерстяных и смесовых тканей Дисс... д. т.н. - Т. - 2015. - 231 с.
DOI: http://dx.doi.org/10.20534/ESR-16-9.10-181-184
Davlyatov Shokhrukh Muratovich, Senior Scientific Worker-Researcher, Tashkent Architecture and Construction Institute, Tashkent, Uzbekistan E-mail: [email protected]
Study of functioning of reservoirs in the form of cylindrical shells
Abstract: Research results of the functioning of steel reservoirs for liquid oil products storing are given in the paper; the reservoirs are produced in the form of cylindrical shells based on the models designed by "ANSYS" computer program (USA).
Keywords: cylindrical shell, steel reservoir, smooth walls, reinforced walls, reinforced cylindrical panel, rolled channel bar, ^section, G-section roll-formed shapes, strength, stability, stress.
The models of steel cylindrical reservoirs with smooth walls The diameter of the reservoir: D=2800 mm (r=1400 mm);
(without the reinforcement) and with reinforced vertical walls along Wall thickness: t = 5 mm.
the generatrix by the elements in the form of cylindrical panels of The dimensions (parameters) of vertical reinforcing elements
plate steel, rolled channel bars, C-section and G-section roll-formed along the entire height of reservoir wall are:
shapes are considered here (Fig.1). Calculations have been conduct- 1. Arc distance of cylindrical panel of plate steel: S=454 mm, t =
ed by «ANSYS» computer program (USA) [1]. =5 mm, A=22,7 cm 2.
The dimensions of reservoir models are taken as: 2. Rolled channels bars № 18 а: h=180 mm, b= 74 mm,
The height of the reservoir H=2960 mm; d=5,1 mm, t = 9,3 mm, A= 22,2 cm 2.
3. G-section equal-flange roll-formed channels (according to State Standards 8278 -83*): h=200 mm, k=100 mm, t=6 mm, A=22,4 cm 2.
4. G-section equal-flange roll-formed shapes 400x160x50x3 mm (according to State Standards 8282 -83*): A=24,01 cm 1
d
b
a — smooth (without the reinforcement) b — reinforced with cylindrical panels c — reinforced with rolled channel bars d — reinforced with C-section equal-flange roll-formed channels; e — reinforced with G-section equal-flange roll-formed shape.
e
Figure 1. Models of studied reservoirs shells
The following reservoir functioning conditions were given: internal working pressure of stored product: P=10 Pa; acceleration of foundation soil: y=4 m/cm 2; design seismicity: 9 points; proper weight of the structure was taken into consideration. Results of changes in strains, normal and tangent stresses in the elements of observed reservoirs are given in the Tables 1 and 2.
The strains in both basic shell of the reservoir and reinforcing panels were determined in X, Y, Z axes, as well as the normal and tangent stresses. The study of reservoir functioning has shown the following results.
Under given conditions of functioning in smooth reservoirs in X- and Y-axes there occur the strains equal to 0,0021 and 0,0020 m, respectively, and in Z-axis the strain is 0,0024. The values of normal stresses are: in X-axis 3,05 • 108 Pa, in Y-axis 3,1 • 108 Pa, and in Z-axis their values are three times less and equal to 1,17 • 108 Pa. Tangent stresses also vary in this manner and their values are tXY = 1,6 • 108, tXZ =1,6 • 108 and tYZ = 4,9 • 107 Pa, respectively.
Table 1. - Strains and stresses in basic shell of the reservoirs
a
c
Indices Smooth reservoir without reinforcement Reservoir with reinforced vertical walls along the generatrix by the elements in the form of
Cylindrical panels of plate steel Rolled channel bars G-section roll-formed shapes G-section roll-formed shapes
Strains in axes, m X 0,0021 0,0019 0,0019 0,004 0,0064
y 0,0020 0,0019 0,0019 0,004 0,011
Z 0,0024 0,00071 0,0006 0,006 0,00023
Normal stresses, Pa ffX 3,05 • 10 8 2,7 • 10 8 3,41 • 10 8 5,5 • 10 8 1,03 • 10 9
3,1 • 10 8 2,9 • 10 8 3,2 • 10 8 5,27 • 10 8 4,06 • 10 8
ffZ. 1,17 • 10 8 6,6 • 10 7 8,6 • 10 7 2,5 • 10 8 6,3 • 10 8
Tangent stresses, Pa TXY 1,6 • 10 8 1,4 • 10 8 1,5 • 10 8 2,76 • 10 8 2,7 • 10 8
TXZ 1,6 • 10 8 4,57- 10 7 5,55 • 10 7 3,2 • 10 8 2,2 • 10 8
T YZ 4,9 • 10 7 4,8 • 10 6 2,66 • 10 7 5,61 • 10 8 2,5- 10 8
Vertical wall reinforcement of reservoir models along the generatrix by the elements in the form of cylindrical panels of plate steel and rolled channel bars has led to the decrease in strains and stresses in the element. Stress-strain states of the models with reinforced vertical walls along the generatrix by the elements in the form of cylindrical panels of plate steel and rolled channel bars were almost identical and their values of strains and normal and tangent stresses were close. After the completion of above effects on the studied models there was observed a loss in stability of reinforcing panels; in the wall of basic shell there occur some minor local losses in stability in the form of small bulging-ins and bulging-outs.
Maximum and minimum tensile and compressive strains in X-and Y-axes are located diametrically opposite in the wall of the reservoir according to the gradient of seismic force effect; in transverse directions their values are much less.
Maximum and minimum tensile and compressive strains in Z-axis are located diametrically opposite in the bottom and upper cover of the reservoir, that is along the height of the structure.
Maximum and minimum normal stresses of tension and compression in X- and Y-axes are located diametrically opposite in the wall of the reservoir according to the gradient of seismic force effect; in transverse directions their values are much less.
Maximum and minimum normal stresses of tension and compression in Z-axis are located diametrically opposite in the bottom and the cover of the reservoir, and in the reinforcing panels; in the wall of the basic shell their values are much less.
Tangent stresses in YZ- and XZ-axes in both the wall of the basic shell and in reinforcing panels have their maximum and minimum values in the points of wall joining with the bottom and the cover; at the same time they are located near the joining of the edges of reinforcing panels with the basic shell.
Stress-strain states of the models with reinforced vertical walls along the generatrix by the elements in the form of ^section and G-section roll-formed shapes are almost identical and their values of strains, normal and tangent stresses are close.
Absolute values of strains in X- and Y-axes in models with reinforced vertical walls along the generatrix by the elements in the form of ^section and G-section roll-formed shapes are greater than in other models; this is the results of the thinness (or wall thickness) of the sections. Maximum and minimum tensile and compressive strains in X-and Y-axes are located diametrically opposite in the walls reinforced by C-section and G-section roll-formed shapes according to the gradient of seismic force effect; in transverse directions their values are much less. Maximum tensile and compressive strains in Z-axis are located in the wall and reinforcing panels, and minimum ones — in the bottom and the upper cover of the reservoir.
Maximum and minimum normal stresses oftension and compression in X- and Y-axes are located diametrically opposite in the wall of the reservoir and reinforcing panels according to the gradient ofseismic force effect; in transverse directions their values are much less. Here a complete loss of stability of all reinforcing panels is observed, and in the basic shell there occur some local losses of stability in the form of wall bulging-out in certain lengths approximately equal to the distances between the reinforcing panels. Here the local losses of stability of the wall of the basic shell are more pronounced and greater in size than in the models reinforced by cylindrical panels and rolled channel bars.
Similar pattern of stress-strain state is observed in Z-axis. Maximum and minimum normal stresses of tension and compression are located in the wall of the reservoir and reinforcing panels.
Maximum and minimum tangent stresses of tension and compression are located in the wall of the reservoir and reinforcing panels. A complete loss of stability of all reinforcing panels is observed, and some local losses of stability in the form of wall bulging-out occur in the basic shell.
The simplest calculations show that when reinforcing the shell with vertical discrete ridges, cylindrical panels of plate steel are the cheapest: 8-9% cheaper than channel bars, 12-13% cheaper than C-section, and 13-14% cheaper than G-section [2].
Maximum and minimum tangent stresses in X- and Y-axes appear in mutual perpendicular planes of reservoir wall. The values of tangent stresses in the bottom and the cover are sufficiently less than the ones in the wall.
Conclusions:
1. Reinforcement of the basic shell of the reservoir along the vertical generatrix with different panels leads to a considerable increase in stability and strength of the structure. Other conditions being equal the most effective are the reinforcing panels in the form of cylindrical panels and rolled channel bars.
2. Stress-strain states of the models with reinforced vertical walls along the generatrix by the elements in the form of cylindrical panels ofplate steel and rolled channel bars are almost identical and their values of strains, normal and tangent stresses are very close.
3. Maximum and minimum tensile and compressive strains in X- and Y-axes are located diametrically opposite in the wall of the reservoir according to the gradient of seismic force effect; in transverse directions their values are much less.
Maximum and minimum tensile and compressive strains in Z-axis are located diametrically opposite in the bottom and the upper cover of the reservoir.
4. Maximum and minimum normal stresses of tension and compression in X- and Y-axes are located diametrically opposite in the wall of the reservoir according to the gradient of seismic force effect; in transverse directions their values are much less. Maximum and minimum normal stresses of tension and compression in Z -axes are located diametrically opposite in the bottom and the cover of the reservoir and in reinforcing panels; on the wall of the basic shell, their values is much less.
5. Maximum and minimum tangent stresses in X- and Y-axes appear in mutual perpendicular planes of reservoir wall. The values of tangent stresses in the bottom and the cover are sufficiently less than the ones in the wall.
Tangent stresses in YZ- and XZ-axes in both the wall of the basic shell and reinforcing panels have their maximum and minimum values in the points of wall joining with the bottom and the cover; at the same time they are located near the joining of the edges of reinforcing panels with the basic shell.
6. Absolute values of strains in X- and Y-axes in models with reinforced vertical walls along the generatrix by the elements in the form of C-section and G-section roll-formed shapes are greater than the ones in other models; this is the results of the thinness (or wall thickness) of the sections.
7. Maximum and minimum normal stresses of tension and compression in X- and Y-axes are located diametrically opposite in the wall ofthe reservoir and reinforcing panels according to the gradient ofseismic force effect; in transverse directions their values are much less. A
Table 2. - Strains and stresses in reinforcing panels of the reservoirs
Indices Reservoir with reinforced vertical walls along the generatrix by the elements in the form of
Cylindrical panels of plate steel Rolled channel bars ^section roll-formed shapes G-section roll-formed shapes
Strains in axes, m X 0,0019 0,0019 0,004 0,053
y 0,0018 0,0019 0,004 0,027
Z 0,0002 0,0006 0,0005 0,00127
Normal stresses, Pa 1,06 • 10 8 1,34 • 10 8 7,33 • 10 8 1,03 • 10 9
1,9 • 10 7 1,67 • 10 7 7,2 • 10 8 1,5 • 10 9
2,7 • 10 7 2,33 • 10 6 2,5 • 10 8 8,9 • 10 7
Tangent stresses, Pa T XY 1,07 • 10 7 1,27 • 10 7 3,9 • 10 8 1,23 • 10 9
TXZ 4,88 • 10 6 3,09- 10 7 3,2 • 10 8 2,2- 10 8
TYZ 4,7 • 10 7 2,66 • 10 8 1,61 • 10 8 4,5 • 10 8
complete loss of stability of all reinforcing panels is observed, and in the basic shell there occur some local losses of stability in the form of wall bulging-out in certain lengths approximately equal to the distances between the reinforcing panels. Here local losses of stability of the wall of the basic shell are more pronounced and greater in size than in the models reinforced by cylindrical panels and rolled channel bars.
Similar pattern of stress-strain state is observed in Z-axis. Maximum and minimum normal stresses of tension and compression are located in the wall of the reservoir and reinforcing panels.
8. Maximum and minimum tangent stresses of tension and compression are located in the wall of the reservoir and reinforcing panels. A complete loss of stability of all reinforcing panels is observed, and some local losses of stability in the form ofwall bulging-out occur in the basic shell.
9. Taking into account the feasibility of manufacturing conditions, the "in-function" cost, it is recommended to use the reinforcing elements in the form of cylindrical panels.
References:
1. Kaplun A. B., Morozov E. M., Olfer'eva M. A. ANSYS in Engineer Hands. A Practical Guide. - Moscow: Nauka, - 2003. - 134 p.
2. Building Code - 2.03.05-97. «Steel structures. Design Standards». Tashkent, - 1997. - 117 p.
DOI: http://dx.doi.org/10.20534/ESR-16-9.10-184-186
Erboyev Shavkat Ochiltoshevich, Jizzakhpolytechnic institute, Senior teacher, E-mail: [email protected]
Organizational and structural measures to improve the process of operation concrete span
Abstract: Ways of improving the structures of exploitation and practical ways of assessment of technical condition of the operated railway flying structures of bridges.
Keywords: bridge constructions, ferroconcrete, flying structures.
Analyzing the present situation of the bridge maintenance, it can be concluded that the Republican roads of JSC "Uzbekistan Railways" ("Uzbekiston Temir Yullari") absolutely don't meet the requirements of a durable and reliable operating structure. Service regular examinations and tests are not well organized and therefore Republican railway does not have a full picture of the technical condition and capacity of operated facilities.
Preservation and maintenance of normalized reliability of the operated bridges — standing problem, requiring for their solution wide variety of organizational activities.
In developing these measures should take into account that exploited the bridges built at different times for different regulations and loads and are in varying condition. Therefore, the collecting and study of the history of operation and organization of repair requires a systematic approach.
The observed reduction of operational reliability of bridge spans, in most cases, should be attributed to poor organization of work operations. However, as mentioned in [1] in the bulk of the work of these units includes repairs to the regulatory structures under overhead bed, track structure on bridges and other works, and repair of the superstructures practical is not given any attention.
Renovations to improve the reliability of a bridge span upon the occurrence of a failure on the basis of endurance of the concrete, require a large amount of restoration work [1], which forces the linear enterprises of the railroads impossible to master. Specialized units of the JSC "Uzbekistan Railways", (Bridge building) where there is a strong mechanized equipment and machines, are not engaged in repair. As a result of solving many of the issues are time consuming, creating every year the danger of injuries, further development of which will restrict load capacity and premature structure failure.
It is unacceptable that many bridge organizations have the distraction of work, not associated with the repair of engineering structures. So, in General, JSC "Uzbekistan Railways" extraneous
load is 22% of the total. Despite the fact that annual allocations for capital repairs of bridges increased at an average rate of 7-8%, the situation does not change.
The way out is only possible with the creation of specialized mechanized units in ATIE (Association of track industry enterprises), organized by the Association of the track in the light of decisions on restructuring of work of railway transport. This does not require increase in staff, and the only restructuring of the production units. The existing small team in the production areas (in track) are combined into one unit headed by the Deputy chief ATIE on artificial structures. Created unit when equipping it with the necessary equipment to perform all repairs, including reinforcement of individual elements of the superstructure and replace them. This creates a separate, centralized, mechanized and industrial mobile base of operation. This allows you to increase the profitability of the repair of bridges [2].
In connection with the establishment of such enterprises should rebuild work bridge test stations at JSC "Uzbekistan Railways". It is necessary to strengthen the link of their created units of the repair of bridges. The estimated structural organization of service operation is given in figure 1.
Part of a bridge-test station to a collection of information about the state operated bridges and control to streamline technical documentation management, headed by a qualified engineer, bridge-builders and technology. The task group is to prepare information on the status ofbridges, identification of the need for test structures with defects and damages.
Inspection and testing of bridges produces a bridge-test station. Along with the traditional examinations and tests depends on the parameters for determining the residual life.
To obtain the most complete picture of the stress strain state of the exploited superstructures appropriate ordering of the data. In the future, these data can be processed and analyzed by computer.
