Experimental studies on the possibility of manufacturing cold bends with increased bending angles

2020 ◽  
Vol 10 (2) ◽  
pp. 127-137
Author(s):  
Grigory V. Nesterov ◽  
◽  
Olga A. Zadubrovskaya ◽  
Dmitry A. Gavrilov ◽  
Pavel V. Poshibaev ◽  
...  
Keyword(s):  
Impact Strength ◽  
Strength Class ◽  
Cold Deformation ◽  
Experimental Studies ◽  
Cold Brittleness ◽  
Rolled Stock ◽  
Regulatory Requirements ◽  
Bending Angle ◽  
Cold Bends ◽  
Cold Brittleness Threshold

Used in order to turn the line of trunk pipelines in horizontal and vertical planes, cold bends are the simplest and most economical elements to be manufactured. Their smaller rotation angle compared with other types of bends is, however, a disadvantage. The article presents the results of cold bends, experimentally manufactured from K56 strength class pipes to have an increased bending angle compared to that stated in regulatory requirements; also, it contains test results regarding metal samples taken from deformed and undeformed sites of the experimental bends. It was found that 720×8 mm and 1020×17 mm bends at rotation angles of up to 13 and 9.1°, respectively, retain satisfactory geometric parameters and are not prone to corrugations. A study on how hardening at cold deformation affects the change in the mechanical properties of deformed bend sites showed that the values of temporary resistance, yield strength, elongation, and impact strength comply with regulatory requirements. It was revealed that the delivery state of the rolled stock of the initial bare pipe affects the level of impact strength and the cold brittleness threshold attributed to the bends: thus, when testing the bent-out metal after high tempering, a higher level of toughness together with a higher cold brittleness threshold were revealed compared to those obtained when testing the bent-out metal after controlled rolling. In general, experimental studies confirmed that cold bends with an increased bending angle could be manufactured from Russian-made pipes of K56 strength class. Such bends used to construct a trunk pipeline will contribute to reducing the total number of bends, the amount of work and, consequently, the cost of construction.

Effect of Wood Filler Concentration on Physical and Mechanical Properties of PLA-Based Composites

2021 ◽  
Vol 887 ◽  
pp. 110-115
Author(s):  
G.A. Sabirova ◽  
R.R. Safin ◽  
N.R. Galyavetdinov
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Composite Materials ◽  
Impact Strength ◽  
Wood Flour ◽  
Experimental Studies ◽  
Physical And Mechanical Properties ◽  
Filler Concentration ◽  
High Concentration

This paper presents the findings of experimental studies of the physical and mechanical properties of wood-filled composites based on polylactide (PLA) and vegetable filler in the form of wood flour (WF) thermally modified at 200-240 °C. It also reveals the dependence of the tensile strength, impact strength, bending elastic modulus, and density of composites on the amount of wood filler and the temperature of its thermal pre-modification. We established that an increase in the concentration of the introduced filler and the degree of its heat treatment results in a decrease of the tensile strength, impact strength and density of composite materials, while with a lower binder content, thermal modification at 200 °C has a positive effect on bending elastic modulus. We also found that 40 % content of a wood filler heated to 200 °C is sufficient to maintain relatively high physical and mechanical properties of composite materials. With a higher content of a wood filler, the cost can be reduced but the quality of products made of this material may significantly deteriorate. However, depending on the application and the life cycle of this product, it is possible to develop a formulation that includes a high concentration of filler.

Hydraulic characteristics and calculation of the innovative systems of surface runoff disposal

2021 ◽  
pp. 46-51
Author(s):  
Ю.В. Брянская ◽  
А.Э. Тен ◽  
Н.Т. Джумагулова ◽  
Г.Н. Громов
Keyword(s):  
Cross Sections ◽  
Surface Runoff ◽  
Experimental Studies ◽  
Drainage System ◽  
Anthropogenic Pollution ◽  
Hydraulic Characteristics ◽  
Regulatory Requirements ◽  
The Subject ◽  
Intensive Development ◽  
Selection Of

В условиях интенсивного развития новых отечественных и зарубежных технологий, материалов и оборудования, применяемых для защиты окружающей природной среды от загрязнений техногенного происхождения, особую актуальность приобретают разработки новых систем отвода и очистки поверхностных сточных вод. Эти системы позволяют использовать последние достижения отраслевой науки и оптимизировать алгоритм выполнения операций и практических приемов их гидравлического расчета. Примером является инновационная система отвода поверхностных сточных вод АСО Qmax, которая относится к открытой системе каналов (лотков) для сбора и отведения поверхностных сточных вод, формирующихся при выпадении атмосферных осадков. Однако широкому применению данного вида конструкций в России препятствует отсутствие методики их гидравлического расчета, в том числе таблиц для подбора сечений (диаметров) каналов, которая бы удовлетворяла требованиям российской нормативно-методической базы проектирования систем отведения поверхностных сточных вод. В этой связи предметом данной статьи явилась оценка гидравлических характеристик трубопроводов, каналов (лотков) системы водоотвода АСО Qmax. Приведены результаты теоретических и экспериментальных исследований гидравлических характеристик системы АСО Qmaxс учетом адаптации для российских условий и нормативных требований, а также обоснование рекомендуемых параметров для их использования. In the context of the intensive development of new domestic and foreign technologies, materials and equipment used to protect the environment from anthropogenic pollution, the development of advanced systems for surface runoff removal and treatment is of special actuality. These systems provide for using the latest achievements of the sectoral science and optimizing the algorithm for performing operations and practical methods for the hydraulic calculations. An example of the innovative surface runoff disposal system is ASO Qmax, that refers to an open system of channels for the collection and disposal of surface runoff formed during precipitation. However, the widespread use of these facilities in Russia is hampered by the lack of a method for the hydraulic calculations, including tables for the selection of cross-sections (diameters) of channels that meet the requirements of the Russian guidelines and regulations for the design of surface runoff disposal systems. In this regard, the subject of this paper is the estimation of the hydraulic characteristics of pipelines, channels of ASO Qmax drainage system. The results of theoretical and experimental studies of the hydraulic characteristics of ASO Qmax system with account of the adaptation for the Russian conditions and regulatory requirements, as well as the justification of the recommended parameters for their use are presented.

Heat-Insulating Composite Material Based on Wood and Polymer Waste

2020 ◽  
Vol 24 (2) ◽  
pp. 28-33 ◽  
Author(s):  
A.S. Kolosova ◽  
E.S. Pikalov ◽  
O.G. Selivanov
Keyword(s):  
Composite Material ◽  
Methylene Chloride ◽  
Experimental Studies ◽  
Raw Material ◽  
Insulation Material ◽  
Pressing Pressure ◽  
Regulatory Requirements ◽  
Deciduous Species ◽  
Waste Products ◽  
Polymer Waste

The results of the development of a raw mixture, which contains a filler obtained by grinding a mixture of small-sized wood waste based on light dirt varieties of coniferous and deciduous species, and a binder obtained by dissolving the waste products from polystyrene foam in methylene chloride, are presented. This mixture allows cold mixing and pressing followed by heat treatment at the boiling point of the solvent. In the course of experimental studies, the influence of the ratio of the mixture components and the pressing pressure on the basic properties and structure of the obtained composite material was established. The composition of the raw material mixture and the pressing were selected to ensure low thermal conductivity in combination with low values of water absorption and swelling density and strength compliant with regulatory requirements. Received thermal insulation material for construction purposes from wood and polymer waste, characterized by large volumes of formation and high rates of accumulation.

Experimental studies of the correlation between fingers bending angle with voltage outputted from GloveMAP

2014 ◽  
Author(s):  
M.F. Ariff Saad ◽  
M. Hazwan Ali ◽  
Khairunizam Wan ◽  
D. Hazry ◽  
A.B. Shahriman ◽  
...  
Keyword(s):  
Experimental Studies ◽  
Bending Angle

Mechanical properties and cold-brittleness threshold of vanadium

1970 ◽  
Vol 12 (1) ◽  
pp. 53-58
Author(s):  
L. P. Vorob'eva ◽  
A. P. Gulyaev ◽  
I. P. Druzhinina
Keyword(s):  
Mechanical Properties ◽  
Cold Brittleness ◽  
Cold Brittleness Threshold

scholarly journals Enhancing Toughness and Impact Strength of Epoxy Resins by Using Hyperbranched Polymers

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Hangyu Park ◽  
Youngson Choe
Keyword(s):  
Molecular Weight ◽  
Impact Strength ◽  
Epoxy Resins ◽  
Impact Resistance ◽  
Experimental Studies ◽  
Molecular Size ◽  
Hyperbranched Polymers ◽  
Phase Separations ◽  
Hyperbranched Poly ◽  
The Impact

Toughened epoxy has been widely used in industrial areas such as automotive and electronics. In this study, nanosized hyperbranched polymers (HBPs) as a flexibilizer are synthesized and embedded into epoxy resin to enhance the toughness and flexibility. Two different HBPs, hyperbranched poly(methylacrylate-diethanolamine) (poly(MA-DEA)) and poly(methylacrylate- ethanolamine) (poly(MA-EA)), were prepared and blended with both epoxy and polyetheramine, a curing agent. The molecular size of HBPs was estimated to be 6 ~ 14 nm in diameter. The molecular weight of HBPs ranges from 1500(1.5 K) to 7000(7.0 K) g/mol. In cured epoxy/HBP blends, no phase separations are occurred, indicating that HBPs possess sufficient miscibility with epoxy. The tensile toughness of the blends increased with changing the molecular weight of HBPs without sacrificing tensile strengths. The impact strength of the blends increases stiffly until the loading % of HBPs in the blends reaches 10 wt%. In addition, the experimental studies showed that impact resistance also increased with an increase in molecular weight of HBPs. The obtained impact resistance of the epoxy/HBP blends with 10 wt% was 270% more effective compared to that of cured neat epoxy.

Kinetics of Residual Stresses in a Welded Frameless Tubular Node

2019 ◽  
Vol 946 ◽  
pp. 921-927
Author(s):  
A.K. Tingaev
Keyword(s):  
High Temperature ◽  
Yield Strength ◽  
Residual Stresses ◽  
Heat Affected Zone ◽  
Strength Class ◽  
Experimental Studies ◽  
Point Of View ◽  
Maximum Value ◽  
Effective Reduction ◽  
Kinetics Of

The results of experimental studies of the variation of residual stresses in a frameless tubular node of the offshore stationary platform (OSP) due to technological effects on the metal are presented. It is shown in the paper that the value of the tensile residual stresses in sheet rolled products with 20-50 mm of thickness reaches 80-65 MPa. As a result of the subsequent technological redistribution, the residual stresses change in magnitude and sign, and reach 0.8-1.2 of the yield strength of the base metal. The most unfavorable from the point of view of the serviceability of OSP are the tensile residual stresses in welded joints, the maximum value of which is 350...500 MPa. High temperature tempering after welding does not always lead to the desired result: in the heat-affected zone of the corner joints of nozzles mounting to the waist tube of the node, the residual stresses amount to 120-150 MPa. Preheating temperatures in the range of 120-1600С do not have a significant effect on the value of residual welding stresses. For more effective reduction of σrs , its value should be 200-4500С, depending on the thickness of the joined parts and the strength class of the steel.

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