scholarly journals Method for determining technological parameters to repair pipeline with out-of-spec curvature

2020 ◽  
Vol 4 (2) ◽  
pp. 84-88
Author(s):  
Victor M. Varshitsky ◽  
◽  
Igor B. Lebedenko ◽  
Eldar N. Figarov ◽  
◽  
...  
Keyword(s):  
Strain State ◽  
Operating Conditions ◽  
Technological Parameters ◽  
Stress Strain ◽  
Line Pipe ◽  
Repair Work ◽  
Stress Strain State ◽  
Actual Operating ◽  
Simulation Results ◽  
Inspection Data

When performing in-line inspection of trunk pipelines, line pipe sections are detected with curvature exceeding the values required by specifications. To prepare a repair work project that entails bringing the pipeline into the standard conditions, it is necessary to determine the technological parameters of the repair. The corresponding technique is known for cases of moving an initially straight pipeline. The authors of the paper have developed the method for determining the technological parameters to repair pipeline with out-of-spec curvature of the axis. The method is based on simulation of pipeline deformation with the initial curvature of the axis, taking into account the actual operating conditions of the pipeline and in-line inspection data. Examples of calculations of repair technological parameters and stress-strain state of pipeline sections with out-of-spec curvature are given. The simulation results confirm the possibility for applying this method to assess the technological parameters of repair, the length of trench excavation, the size and limits of the pipeline additional burying or lifting, and to determine the stress-strain state of the pipeline section under repair during and after repair work.

Method for determining process parameters in the repairing of pipelines with out-of-spec curvature

2020 ◽  
Vol 10 (1) ◽  
pp. 17-21
Author(s):  
Victor M. Varshitsky ◽  
◽  
Igor B. Lebedenko ◽  
Eldar N. Figarov ◽  
◽  
...  
Keyword(s):  
Process Parameters ◽  
Strain State ◽  
Repair Process ◽  
Operating Conditions ◽  
Stress Strain ◽  
Pipeline Section ◽  
Stress Strain State ◽  
Actual Operating ◽  
Deformed State ◽  
Inspection Data

Pipe sections with curvatures exceeding the required specified values are often found during the pigging of major pipelines. Process parameters for repairs have to be defined in order to develop a maintenance project that also includes works to restore the specified status of the section found. A corresponding method is known for cases of relocation of an initially straight pipeline. The authors developed a method for determining process parameters for repairing pipelines with out-of-project axis curvature. The method is based on modeling the deformation of a pipeline with initial axis curvature; it takes into account the actual operating conditions of the pipeline and in-line inspection data. Examples of calculating process parameters for repairs and stress-deformed state of pipeline sections with out-of-specs curvature have been presented. The modeling results confirm the possibility of using the method for evaluating the repair process parameters, the length of the required trench exposure, and the magnitude and boundaries of additional digging-in or the need to lift the pipeline in order to determine the stress–strain state of the pipeline section to be repaired during execution and after the completion of repairs.

scholarly journals Modeling and assessment of the stress-strain state of above-ground pipelines at different types of compensation sections

2021 ◽  
Vol 266 ◽  
pp. 01022
Author(s):  
Z.A. Besheryan ◽  
I.F. Kantemirov
Keyword(s):  
Strain State ◽  
Complex Stress ◽  
Operating Conditions ◽  
The Arctic ◽  
Design Parameters ◽  
The Finite Element Method ◽  
Stress Strain ◽  
Stress Strain State ◽  
Actual Operating ◽  
Different Types

The development of Russian fuel and energy complex in the short term is connected with the development of new hydrocarbon field in the permafrost zone and the need to build Arctic pipelines north of the 60th parallel. The ground-based structural scheme of pipeline laying is the most optimal while constructing trunk pipelines in permafrost areas in the Arctic and subarctic latitudes. The actual operating conditions of these systems are insufficiently studied. The above-ground pipeline in permafrost is in an complex stress-strain state. This study presents the results of the assessment of the stress-strain state of linearly extended above-ground pipelines at different compensation sections (triangular compensator; trapezoidal compensator; U-shaped compensator) under actual operating conditions. Using the finite element method on mathematical models, the dependences of the transverse displacements of the pipeline on movable supports and stresses arising in dangerous sections of the typical pipeline section during self-compensation of deformations on the variable design parameters of the system for various load combinations were established (the simulation was carried out in the ANSYS software package).

scholarly journals CONTROL OF ACTIONS OF STEEL TANK IN WORKING

2018 ◽  
Vol 22 (4) ◽  
pp. 66-74 ◽  
Author(s):  
A. A. Vasilkin
Keyword(s):  
Strain State ◽  
Low Cycle Fatigue ◽  
Operating Conditions ◽  
Maximum Effect ◽  
Safe Operation ◽  
Stress Strain ◽  
Load Bearing ◽  
Stress Strain State ◽  
Steel Tank ◽  
Steel Tanks

In steel tanks made by the method of rolling, defects of a geometric shape often occur in the area of the welded welded joint of the wall. Subsequently, in these areas, as a result of low cycle fatigue, an unacceptable defect appears in the form of a crack, which makes it necessary to remove the reservoir from operation and carry out a set of measures for its repair. To determine the terms of safe operation of vertical steel tanks with geometric defects, it is proposed to use the methodology control of the actions of structures of load-bearing structures, one of the directions of which is the regulation of the stress-strain state of steel structures. To implement the possibility of regulating construction, it is necessary to identify such parameters, the change of which will give the maximum effect in achieving the set goals. As the indicated parameters, the design characteristics (material properties, design scheme, geometric characteristics) and factors of external influences (load, operating conditions) can act. To regulate the stress-strain state design of vertical steel tanks, the following regulators are proposed: product loading height, wall deflection arrow and permissible number of tank loading cycles. By numerical calculation of the VAT of the vertical steel tank design with geometric defects, the necessary values and values of the stress state are determined. Further, using known analytical dependencies from the field of fracture mechanics, it is possible to determine the permissible number of loading cycles of the reservoir before the appearance of a crack-like defect. The application of the methodology control of the actions of structures load-bearing structures, by means of a certain change in the established control parameters, allows increasing the number of loading cycles of the reservoir, thereby increasing the period of safe operation of the defective reservoir and thereby increasing the economic efficiency of the tank farm.

3D Simulation of Stress-Strain State of Plasma Arc Surfacing by CAD/CAE Software Sysweld

2014 ◽  
Vol 1029 ◽  
pp. 1-7
Author(s):  
Rayna Dimitrova ◽  
Alexander Nedelchev ◽  
Antonio Nikolov
Keyword(s):  
Deformation Process ◽  
Strain State ◽  
3D Simulation ◽  
Visual Environment ◽  
Plasma Arc ◽  
Technological Parameters ◽  
State Distribution ◽  
Stress Strain ◽  
Stress Strain State ◽  
Cae Simulation

The deformation process during the plasma arc surfacing is analyzed by CAD/CAE software SysWeld under Visual Environment using 3D simulation. The aim of simulation is visualization of a temperature field and a stress-strain state distribution as resul ts of surfacing under typical technological parameters of plasma arc processing which could be used for education. Key w ords : CAD/CAE simulation , plasma arc surfacing , stress-strain state

scholarly journals Stress-strain state analysis of the design of full-turning vertical empennage for aero-spacecraft

2021 ◽  
Vol 22 (1) ◽  
pp. 36-42
Author(s):  
Andrey A. Chistyakov ◽  
Valery P. Timoshenko
Keyword(s):  
Numerical Simulation ◽  
Strain State ◽  
Dynamic Pressure ◽  
Operating Conditions ◽  
Structural Scheme ◽  
Stress Strain ◽  
Mechanical Loads ◽  
Stress Strain State ◽  
Distributed Load ◽  
Calculation Results

In this work, the most rational schemes to designing the skin of a full-turning vertical empennage element (stabilator) have been studied. Skin designing schemes were chosen according to aero-spacecraft operating conditions in the re-entry trajectory. During designing process, the requirements for reusable structures of tourist-class aero-spacecrafts were taken into account, such as: maximum simplicity and endurance of the product. To determine the mechanical loads acting on the keel during its movement in the air, a numerical simulation of the aerodynamic flow-around the stabilator profile at 5 arbitrary points on the flight path was carried out. The parameters used for the analysis are: flight velocity, density and viscosity of the air. Of the 5 obtained fields of dynamic pressure acting on the stabilator, the field that creates the largest distributed load was used as the boundary condition for the analysis of the stress-strain state of the structure. The problem of mechanical loading of the stabilator was solved separately for each of the previously studied structural schemes of the skin. Based on the obtained calculation results the optimal skin structural scheme was chosen by comparing the displacements on the line connecting ribs.

scholarly journals Development of a Nonlinear Dependence for Determining the Stress-Strain State of the Pipeline-Composite Bandage System

2021 ◽  
Vol 248 ◽  
pp. 04024
Author(s):  
Robert А. Ramazanov ◽  
Igor F. Kantemirov ◽  
Denis A. Gulin ◽  
Indira F. Makhmudova ◽  
Zulfiya F. Ismagilova
Keyword(s):  
Polymer Composite ◽  
Strain State ◽  
Polymeric Materials ◽  
Polymer Materials ◽  
Nonlinear Dependence ◽  
Technical Diagnostics ◽  
Stress Strain ◽  
Repair Work ◽  
Industrial Enterprises ◽  
Stress Strain State

The range of applications of polymeric materials in the oil and gas industries is expanding every year. For example, at present, a number of industrial enterprises are engaged in the production of various tape polymer composite structures that are used to repair pipelines. They are widely used due to the significant advantages of polymeric materials over steel such as low costs, low weight, corrosion resistance and strength. Moreover, most of the operated pipelines are about to reach their standard service life. In the course of technical diagnostics, a significant number of defects of mechanical origin from external influences are constantly revealed. Repair work on pipelines must fully restore the bearing capacity of the site. Therefore, the use of polymer materials for pipeline repair is an important task. Here, we propose to use polymer composite bandages, which will increase the overhaul period. However, a coherent methodology for choosing a material and calculating the required thickness of this structure is not available in the literature, and, therefore, the purpose of this work was to develop such a methodology, as well as to assess the stress-strain state of pipeline-bandage systems. The method presented in this work takes into account the possible anisotropy of the shroud material in the longitudinal and transverse directions and the possibility of plastic deformation of the pipeline material in the annular direction. This work is based on the following assumptions: (a) bilinear dependence of stress on deformation for steel; (b) plastic deformations of the band material are absent; and (3) absolute adhesion between the pipeline and the band. The paper presents the analysis of the market of polymeric materials for pipeline repair, their key properties, and the minimum thickness of the band made of these materials was calculated for various values of the stress concentration coefficient.

Ensuring the strength and stability of the tank wall during repairs by installing rigid frames

2021 ◽  
pp. 152-165
Author(s):  
Артем Николаевич Задумин ◽  
Евгений Григорьевич Ильин ◽  
Михаил Владимирович Лиховцев ◽  
Алексей Александрович Катанов
Keyword(s):  
Computer Modeling ◽  
Strain State ◽  
Mutual Influence ◽  
Tank Wall ◽  
Stress Strain ◽  
Stability Calculation ◽  
Actual Structure ◽  
Repair Work ◽  
Stress Strain State ◽  
Cutting Out

Устранение дефектов металла и сварных швов стенок вертикальных цилиндрических резервуаров возможно методом вырезки и замены удаленных фрагментов ремонтными вставками с использованием рам жесткости. При этом в нормативных документах отсутствуют методики расчета таких усиливающих элементов и собственно конструкции стенки резервуара с данными элементами. С целью оценки прочности и устойчивости стенки резервуара и рамы жесткости во время проведения ремонтных работ выполнено компьютерное моделирование и проведены расчеты напряженно-деформированного состояния указанных металлоконструкций. В рамках исследования рассмотрены основные российские и зарубежные нормативные документы, регламентирующие нагрузки и методики расчета устойчивости стенки резервуара, проанализированы публикации, посвященные расчету устойчивости стенки резервуара с применением компьютерного моделирования. Приведены результаты компьютерного моделирования и расчетов на прочность и устойчивость в зависимости от снеговой и ветровой нагрузок. По итогам выполненных работ сделаны следующие выводы: 1) расчеты должны учитывать ветровую нагрузку, действующую под углом 40° к вырезаемому фрагменту; 2) допустимые размеры одной вставки не должны превышать габариты одного листа пояса резервуара; 3) не рекомендуется одновременная вырезка и замена более чем одного фрагмента; 4) при необходимости возможность одновременной вырезки проемов в двух и более местах должна определяться расчетом, учитывающим взаимное влияние количества, расположения и размеров проемов на напряженно-деформированное состояние стенки резервуара и рам жесткости. Elimination of metal defects and welds in the walls of vertical cylindrical tanks is possible by cutting out and replacing the removed fragments with repair inserts using stiffening frames. At the same time, there are no methods for calculating such reinforcing elements and the actual structure of the tank wall with these elements in the regulatory documents. In order to assess the strength and stability of the tank wall and the stiffening frame during the repair work, computer modeling was performed and the stress-strain state of these metal structures was calculated. Within the framework of the research the main Russian and foreign normative documents regulating the loads and methods of tank wall stability calculation are considered; the publications devoted to the tank wall stability calculation by means of computer modeling are analyzed. The results of computer modeling and calculations for strength and stability depending on snow and wind loads are presented. Results of the research performed were used to make the following conclusions: 1) calculations should take into account the wind load, acting at an angle of 40° to the section to be cut out; 2) the allowable dimensions of one insert should not exceed the dimensions of one sheet of the tank ring; 3) simultaneous cutting out and replacement of more than one section is not recommended; 4) if necessary simultaneous cutting of openings in two or more places should be determined by calculation, taking into account the mutual influence of the number, location and sizes of openings on the stress-strain state of the tank wall and stiffening frames.

scholarly journals Modeling the stress-strain state of a circular plate subject to general corrosion according to various models

2021 ◽  
Vol 263 ◽  
pp. 03009
Author(s):  
Ilya Ovchinnikov ◽  
Vladimir Avzovin
Keyword(s):  
Experimental Data ◽  
Stress State ◽  
Circular Plate ◽  
Strain State ◽  
Corrosive Wear ◽  
Operating Conditions ◽  
General Corrosion ◽  
Stress Strain ◽  
Stress Strain State ◽  
Kinetics Of

Quite a lot of works have been devoted to the problem of modeling the behavior of thin-walled structures exposed to an aggressive environment leading to corrosive wear of their surface. Researchers have proposed a fairly large set of models of corrosive wear, taking into account the influence of various factors on the kinetics of corrosion (time, material, temperature, the nature of the corrosive environment, the stress-strain state of the structure). Moreover, different authors often propose different models for the same conditions. In the article under consideration, a rather unique comparative study of three corrosion models proposed by different authors (Dolinsky V.M., Gutman E.M., Ovchinnikov I.G.) was carried out to simulate the behavior of the same circular plate subjected to the combined action of load and corrosion wear and tear. Moreover, the identification of the models, that is, the determination of the coefficients included in them, was carried out using the same experimental data. These models were then used to simulate the behavior of plates subject to corrosive wear under various loads. The results of numerical simulation were compared with experimental data obtained during testing of corrosive plates. Interestingly, in the models used, the effect of the stress state on the kinetics of corrosion was taken into account using different invariants of the stress state: the stress intensity in V.M. Dolinsky, medium voltage in the model of E.M. Gutman, and the specific energy in the model of I.G. Ovchinnikov. The analysis showed that the difference from the experiment when using the three models considered does not exceed 9.3%. The discrepancy between the results obtained using different models is also within the acceptable range, which suggests that all three models can be used to predict the behavior of plates under corrosive wear conditions. However, it is of interest to conduct research on the predictive capabilities of models on large forecast arms that go beyond the scope of experimental studies. At the same time, carrying out numerical experiments to simulate the behavior of complex structures in a stressed state and subject to corrosive wear, using several models that allow a good description of the experimental data and the most complete consideration of the operating conditions, makes it possible to obtain a more complete and versatile picture of what is happening in design processes, in comparison with the calculations performed according to one model, even if it describes the experimental data well.

scholarly journals RESEARCH AND EXPERIMENTAL STUDIES OF STRESS-STRAIN STATE OF DISCRETE-CONTINUAL HARDENED MACHINE PARTS

2021 ◽  
pp. 5-21
Author(s):  
Oleg Veretelnik ◽  
Mykola M. Tkachuk ◽  
Serhii Kravchenko ◽  
Mariia Saverska ◽  
Serhii Kutsenko ◽  
...  
Keyword(s):  
Strain State ◽  
Experimental Studies ◽  
Technological Parameters ◽  
Stress Strain ◽  
Stress Strain State ◽  
Hardening Process ◽  
Contact Loads ◽  
Machine Parts ◽  
Keywords Stress ◽  
Strength And Durability

Research and experimental studies of stress-strain state of discrete-continual hardened machine parts are presented in this work. This hardening method is distinguished by incorporation of numerous hard spots into the surface layer of one of the bodies. Meanwhile the other part is covered by a continuous corundum layer. Correspondingly, a network of microchannels for lubricant is formed between the bodies. Furthermore the contact loads are intensified in the vicinity of the harder material in the discrete zones. As a result the strength and durability of the loaded parts is increased. The technological parameters of the hardening process have great impact on the resulting characteristics. In particular, this concern the shape of the discrete hardening zones and the material properties of the corundum layer. These factors were varied in stress-strain analyses of the contacting bodies. The dependence of the stress-strain state characteristics on the varied parameters was established. The justified recommendations regarding the technological parameters of the discrete-continual hardening have been developed. Keywords: stress-strain state,  discrete-continual hardening,  contact interaction, finite element method, contact pressure, machine parts

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