scholarly journals Optimization of flat-oval pipes and perspectives of their application in core structures

2018 ◽  
Vol 251 ◽  
pp. 03015
Author(s):  
Alexander Marutyan ◽  
Tamazi Kobaliya ◽  
Evgeny Galdin

The calculation of optimal parameters of flat-oval pipes is given by an approximate method, the correctness of which is confirmed by testing using standardized profiles. A new layout of gratings made of flat-oval shaped pipes is presented, developed for truss systems based on steel rod structures of coatings with replacement of bar-shaped bent elements with tubular ones. The caseless junctions of belts and lattices with direct joining of rod elements to each other without alignment are developed, as well as with structural eccentricities limited to 0.25 of the height of the waist elements, which allows not to take them into account in calculations and provides an increase in the degree of unification of the nodes of the upper and lower belts of carrier’s constructions. The prospects of using a new technical solution in light metal structures of buildings and structures are shown. The area of its rational application is outlined, where by means of variant design of typical, known and new solutions, a quantitative estimate of the reduction in the consumption of structural material is given. The whole diagram of changes in the design parameters of flat-oval pipes is shown in the transformation of their cross-sections from vertical configurations to horizontal ones, including the transition through the outline of a circular shape.

2018 ◽  
Vol 251 ◽  
pp. 03016
Author(s):  
Alexander Marutyan ◽  
Tamazi Kobaliya ◽  
Evgeny Galdin

A new technical solution for re-profiling round tubes into flat-oval ones with a ratio of 1 / 3,064 is presented, which increases their bending strength. The calculation of the optimal parameters of thin-walled sections of the flat-oval shape is given by an approximate method, the correctness of which is confirmed by testing from the standard profiles used. This calculation is repeated with respect to thin-walled sections of the oval shape. The whole diagram of changes in the design parameters of flat-oval and oval pipes is presented in the transformation of their cross-sections from vertical configurations to horizontal ones, including the transition through the outline of a circular shape. The comparative analysis of optimized cross sections of flat oval, oval and round tubes is carried out taking into account the elastic and elastic-plastic deformations of the structural material, where the length of the midline of the thin-walled section is taken as the dividing line between these deformations. The choice is substantiated in favour of flat-oval profile pipes due to their simpler shape including faces of constant curvature (flat and semi-circular), relatively low cost, lower height, greater compactness, higher resistance moment.


2020 ◽  
Vol 1 (2) ◽  
pp. 110-116
Author(s):  
Ol’ga Rashidovna PANFILOVA ◽  
◽  
Natal’ya Vladimirovna DYORINA ◽  
Vladimir Semenovich VELIKANOV ◽  
◽  
...  

The relevance of the work is due to the need to reduce the metal consumption of mining vehicles while maintaining the strength characteristics of their metal structures. An effective tool for finding the best option for combining the design parameters is optimization theory from the point of view of obtaining the design with the required properties. The implementation of the principles and approaches of this theory in relation to the metal structures of mining transport vehicles allows achieving a combination of their geometric characteristics, which makes it possible to obtain the smallest mass and dimensions. Purpose of the work: development of the principle of obtaining mathematical dependencies, allowing to determine the most suitable shape and size of the cross section for the elements that make up the metal structures of mining vehicles, taking into account the direction of the loads perceived by each element. Research methodology. An optimization approach is used, including the definition of the design parameters, the formulation of the objective function and the restrictions imposed on the design parameters. Results and their application. The factors affecting the value of the optimal parameters in the elements of the metal structures of mining vehicles are established. The optimal parameters of the cross section are substantiated for various combinations of the perceived load direction and the priority requirements for metal construction. The obtained recommendations can be applied in the design of frames with a minimum weight or dimensions. Conclusions. The recommendations presented allow us to reasonably choose the best cross-sectional shape of the metal elements of mining transport vehicles, depending on the direction of the current loads. The requirements for metal construction, such as minimum metal consumption and (or) surface area, are taken into account. For rods working in tension or compression, the most rational is the square shape of the cross section. For bending elements, a rectangular section with a height/width ratio of two is best suited. These conclusions are drawn from considerations of the least metal consumption and the smallest surface area of the metal structure. Taking the proposed recommendations into account when designing the metal structures of mining transportation machines will allow us to obtain the lowest values of metal consumption, and, consequently, the cost of the machine with the required technical characteristics.


2019 ◽  
Vol 1 (3) ◽  
pp. 1-10
Author(s):  
Mikhail M. Konstantinov ◽  
Ivan N. Glushkov ◽  
Sergey S. Pashinin ◽  
Igor I. Ognev ◽  
Tatyana V. Bedych

In this paper we consider the structural and technological process of the combine used in the process of separate harvesting of grain crops, as well as a number of its parameters. Among the main units of the combine, we allocate a conveyor and devices for removing beveled stems from under the wheels of the vehicle. The principle of operation of the conveyor at different phases of the Reaper and especially the removal of cut stems from under the wheels of the vehicle during operation of the Reaper. The results of theoretical studies on the establishment of the optimal design of the parameters of the belt conveyor are presented, the ranges of their optimal values are considered and determined. Studies on the establishment of optimal parameters of the screw divider in the Reaper, which is the main component of the device for removal of beveled stems, are presented. Taking into account the optimal design and mode of operation of the screw divider, the correct work is provided to remove the cut stems from under the wheels of the harvester.


Author(s):  
Nataliia Fialko ◽  
◽  
Alla Stepanova ◽  
Raisa Navrodskaia ◽  
Svetlana Shevchuk ◽  
...  

The results of optimizing the parameters of the heat recovery system of a boiler plant designed to heat return water are presented. The feasibility of using a technique that combines methods of exergy analysis experimental planning theory and multilevel optimization to optimize plant parameters is analyzed. It is emphasized that the efficiency of heat recovery systems optimized using the above technique is 2-3% higher than the efficiency of systems optimized using other optimization techniques. In addition, the specified method allows to take into account a significant part of the technical losses in the heat recovery system and to optimize a large number of parameters. The main stages of a comprehensive methodology are given. At each stage, the above methods are used to develop mathematical models and obtain dependences of exergy efficiency criteria on the parameters of the heat recovery system. The results of calculating the optimum values of operating and design parameters for the considered heat recovery system of the boiler unit are presented.


Author(s):  
Sayed M. Metwalli ◽  
M. Alaa Radwan ◽  
Abdel Aziz M. Elmeligy

Abstract The convensional procedure of helical torsion spring design is an iterative process because of large number of requirements and relations that are to be attained once at a time. The design parameters are varied at random until the spring design satisfies performance requirements. A CAD of the spring for minimum weight is formulated with and without the variation of the maximum normal stress with the wire diameter. The CAD program solves by employing the method of Lagrange-Multipliers. The optimal parameters, in a closed form are obtained, normalized and plotted. These explicit relations of design variables allow direct evaluation of optimal design objective and hence, an absolute optimum could be achieved. The comparison of optimum results with those previously published, shows a pronounced achievement in the reduction of torsion spring weight.


2018 ◽  
Vol 210 ◽  
pp. 02023
Author(s):  
Jan Skovajsa ◽  
Martin Zálešák

The article deals with the economic evaluation of investment and optimization of the solar water heating system for family houses. From the point of view of solar systems, the optimal solution is based on the specific application of it. The design is dependent on the location of solar thermal collectors and ration between active aperture area and real daytime consumption. Common calculations according to actual standards often give overstated results, which also reflected in the value of the investments. The article presents the research of optimal parameters of the thermal solar system for preparing of domestic hot water. A combination of related standards and software TRNSYS are used to find optimal parameters. Thanks to created and verified simulation models, it is possible to design parameters so as to avoid under-dimensioning or over-dimensioning of the solar system. Energy price is another factor affects the payback period of investments. This is affected by the used energy sources and their combination. For example, buildings that use electricity to heat water or heating have different energy charges than a building that uses natural gas. So, the aim is to find technically and economically efficient solution.


2013 ◽  
Vol 8-9 ◽  
pp. 277-284
Author(s):  
Olar Radu ◽  
Traian Onet

The nanometric scale researches results can be found, in present, in every industry domains, due to the effects of the new products, obtained on the basis of this researches. In the concrete industry, the research goal at this level is to obtain, finally, a material with new features, whose structural behavior to be considerably better than of the current one. Basically, it aims to achieve, using nanotechnologies, a new structural material for constructions, starting from the current concrete advantages (good compressive strength, durability, etc.), eliminating the disadvantages (low tensile resistance, cracks, etc.), and controlling, in the same time, the costs. Thus, in this paper are presented the required parameters in order to obtain this kind of material, by highlighting the nanocomponents characteristics and the quantities that are used to achieve the expected quality requirements. The real time influence of these nanocomponents on the quality of the studied material can be observed using a dedicated software, specially developed for this purpose.


Author(s):  
Damiano Pasini ◽  
S. C. Burgess ◽  
D. J. Smith

This paper presents a new method for modelling the efficiency of large-scale structural forms. Parametric equations, which include all design parameters and also the effect of buckling, are developed. Shape transformers, envelope efficiency parameter and scaling factor are introduced to describe the geometrical properties of cross-sections and to allow interaction between form and cross-sectional shape selection. Design charts provide insight and understanding and assist the selection of different structural concepts at the preliminary stage of design.


2018 ◽  
Vol 8 (1) ◽  
pp. 117-123
Author(s):  
Vera V. VAKHNINA ◽  
Aleksey A. KUVSHINOV ◽  
Vladimir N. KUZNETSOV ◽  
Vladimir A. SHAPOVALOV

A technique for modeling the magnetic fi elds of power transformers in the environment of the software product FEMM 4.2 is developed taking into account the design scheme and real geometric dimensions of the magnetic system and tank, quasi-permanent current components in high-voltage windings, and the experimental magnetization characteristics of electrical and structural steel. Modeling of magnetic fi elds of magnetic systems of rod and armored rod structures is carried out on the example of serial power transformers TRDN- 63000/115 / 6.3 / 6.3 and TDTs-400000/242/20. The dependences of the mean values of induction in the central cross sections of the rods and side yokes on the quasi-constant currents are determined. It is shown that the saturation of the magnetic system of the rod structure begins with the outer rods at a multiplicity of quasi-constant current equal to 2.2 relative to the nominal phase current of the high-voltage winding. The saturation of the magnetic system of the armored rod structure begins with the lateral yokes at a multiplicity of the quasi-constant current equal to 2.63 with respect to the idle current rating.


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