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

Author(s):  
Victor M. Varshitsky ◽  
◽  
Igor B. Lebedenko ◽  
Eldar N. Figarov ◽  
◽  
...  

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.

2020 ◽  
Vol 4 (2) ◽  
pp. 84-88
Author(s):  
Victor M. Varshitsky ◽  
◽  
Igor B. Lebedenko ◽  
Eldar N. Figarov ◽  
◽  
...  

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.


2021 ◽  
Vol 266 ◽  
pp. 01022
Author(s):  
Z.A. Besheryan ◽  
I.F. Kantemirov

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).


2018 ◽  
Vol 22 (4) ◽  
pp. 66-74 ◽  
Author(s):  
A. A. Vasilkin

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.


2016 ◽  
Vol 685 ◽  
pp. 186-190 ◽  
Author(s):  
Е.V. Eskina ◽  
E.G. Gromova

The paper describes the method of manufacture of profiles in cramped bending conditions using polyurethaneThe scope of studies included stress-strain state of elastic die and parent sheet, as well as the influence of the basic process parameters on characteristics of the produced items using ANSYS software.


2021 ◽  
Vol 2131 (3) ◽  
pp. 032095
Author(s):  
M V Ariskin ◽  
D O Martyshkin ◽  
I V Vanin

Abstract Design models of single-component and three-component samples were developed on glued fiberglass washers in order to investigate the stress-strain state (SF) of the elements of joints of wooden structures. The picture and the nature of the actual stressed-deformed state of the wooden element with glued washers are obtained. Quite high bearing capacity of wooden structures connection is shown.


2021 ◽  
Vol 22 (1) ◽  
pp. 36-42
Author(s):  
Andrey A. Chistyakov ◽  
Valery P. Timoshenko

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.


World Science ◽  
2019 ◽  
Vol 1 (1(41)) ◽  
pp. 11-14
Author(s):  
O. V. Boіko ◽  
A. O. Boiadzhi ◽  
O. M. Korshak

In this work the use of wooden I-beams with OSB wall as the load bearing elements for polygonal arch coverings of buildings of various spans are considered. Special steel connecting pieces can shape the polygonal arch coverings. Calculations of the constructions with a span of 12 and 18 meters and an analysis of their stress-strain state are given.


2021 ◽  
Vol 316 ◽  
pp. 340-345
Author(s):  
A.M. Rekov

Experimental densities of intensity distribution for main deformations, as well as the stress strain state of a metal on the side edges of an aluminum strip during its flat rolling, have been determined. Strain, spread and extrusion ratio have been evaluated. The dimensions of the strip cross-section have been chosen in a way that minimizes spreading. Therefore, the deformed state under rolling is close to a flat one. The correlation between the deformation intensity and the stress-strain state of macro-volumes occurred on strip edges has been estimated. The parameters of two-dimensional probability-density function for the joint distribution of deformation intensity and the Nadai-Lode stress-strain parameter have been determined. Distribution densities for longitudinal, transverse deformations and the intensity of main deformations in the zone of strip rolling are bimodal, which corresponds to both forward and backward slip zones under rolling. The results of the work can be used to predict the depletion of plasticity resources during strip rolling.


2018 ◽  
Vol 931 ◽  
pp. 60-65 ◽  
Author(s):  
Aleksey N. Beskopylny ◽  
Elena E. Kadomtseva ◽  
Grigory P. Strelnikov

In this paper, we consider the influence of the conditions for fixing a wavy plate lying on an elastic foundation on its stressed-deformed state. The profiled plates are widely used in construction practice as fencing structures, for siding works, for roofing and others. The stress-strain state of the wavy plates varies depending on geometry, materials mechanical properties, foundation characteristics and boundary condition. Steel with polymer coatings, which make the sheets a decorative material, is increasingly used in individual and low-rise buildings. The elastic foundation is considered as Winkler base, so we suppose that the reaction of the base is directly proportional to the deflection of the plate at each point. The Bubnov-Galerkin method is used to determine the stress-strain state of the plate. To solve the problem, we use special orthogonal Legendre polynomials satisfying the boundary conditions: simply supported and clamped edges. The results of the calculations were compared for different types of fixation.


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