Influence of the Longitudinal Compressive Force on Parametric Vibrations and Dynamic Stability of Thin-Walled Above-Ground Steel Oil Pipelines with Large Diameter

2017 ◽  
pp. 666-678
Author(s):  
Vladimir Sokolov ◽  
Igor Razov
Keyword(s):  
Dynamic Stability ◽  
Large Diameter ◽  
Compressive Force ◽  
Parametric Vibrations ◽  
Oil Pipelines ◽  
Thin Walled

scholarly journals Free oscillations of thin-walled bimetallic pipelines of large diameter on an elastic foundation

2018 ◽  
Vol 193 ◽  
pp. 02027
Author(s):  
Vladimir Sokolov ◽  
Igor Razov ◽  
Evgeniy Koynov
Keyword(s):  
Elastic Foundation ◽  
Nuclear Power ◽  
Large Diameter ◽  
Compressive Force ◽  
Free Oscillations ◽  
Working Pressure ◽  
Momentum Theory ◽  
Internal Working ◽  
Nonlinear Version ◽  
Thin Walled

In the article, solutions are obtained for a thin-walled bimetallic pipeline. Solutions are obtained, and the frequencies of free oscillations are investigated taking into account the internal working pressure, the longitudinal compressive force, and the elastic foundation. The solutions were obtained on the basis of a geometrically nonlinear version of the semi-momentum theory of cylindrical shells of the middle bend. The proposed calculations can find application in the nuclear power industry, aviation, and the petrochemical industry.

scholarly journals Investigation of the frequencies of free oscillations of the above-ground main pipelines depending on the type of fastening

2018 ◽  
Vol 193 ◽  
pp. 02033
Author(s):  
Vladimir Sokolov ◽  
Igor Razov ◽  
Evgeniy Koinov ◽  
Alexander Korkishko
Keyword(s):  
Large Diameter ◽  
Compressive Force ◽  
Gas Pipeline ◽  
Free Oscillations ◽  
Bending Vibrations ◽  
Working Pressure ◽  
Internal Working ◽  
Main Pipelines ◽  
Thin Walled ◽  
Free Bending

In this paper, we solve the problem of free bending vibrations of a thin-walled gas pipeline of large diameter laid above the ground on supports. The gas pipeline is considered as a cylindrical shell subject to the action of a stationary internal working pressure, the parameter of the longitudinal compressive force. The frequencies of free oscillations and the influence of parameters on the gas pipeline are compared with different versions of the supports.

scholarly journals Free oscillations of thin-walled bimetallic pipelines of large diameter on an elastic foundation

2018 ◽  
Vol 239 ◽  
pp. 06008
Author(s):  
Vladimir Sokolov ◽  
Igor Razov ◽  
Evgeniy Koynov
Keyword(s):  
Elastic Foundation ◽  
Nuclear Power ◽  
Large Diameter ◽  
Compressive Force ◽  
Free Oscillations ◽  
Working Pressure ◽  
Momentum Theory ◽  
Internal Working ◽  
Nonlinear Version ◽  
Thin Walled

In the paper, solutions for a thin-walled bimetallic pipeline are obtained. The frequencies of free oscillations are investigated, taking into account the internal working pressure, the longitudinal compressive force, and the elastic foundation. The solutions were obtained on the basis of a geometrically nonlinear version of the semi-momentum theory of cylindrical shells of the middle bend. The proposed calculations can be used in the nuclear power industry, aviation, and petrochemical industry.

scholarly journals Influence of the length parameter of an underground oil pipeline on the frequency of free oscillation

2020 ◽  
Vol 164 ◽  
pp. 03024
Author(s):  
Sokolov Vladimir ◽  
Igor` Razov ◽  
Andrey Dmitriev
Keyword(s):  
Large Diameter ◽  
Longitudinal Direction ◽  
Soil Conditions ◽  
Attached Mass ◽  
Natural Oscillations ◽  
Oil Pipeline ◽  
Elastic Resistance ◽  
Oil Pipelines ◽  
Modes Of Vibration ◽  
Thin Walled

The problem of finding the natural frequencies of thin-walled underground oil pipelines is solved, based on the application of a semi-momentless theory of cylindrical shells of medium bending, in which bending moments in the longitudinal direction are not taken into account in view of their smallness compared with moments acting in the transverse direction. The solution to this approach is a fourth-order homogeneous differential equation satisfying the boundary conditions of articulation at each end. This equation includes the parameters of the length, internal pressure, thinness of the pipeline, as well as the values of the coefficient of elastic resistance of the soil, the attached mass of the soil and the attached mass of the flowing oil. Based on the data obtained by the derived formulas, the frequency characteristics of large-diameter thin-walled underground oil pipelines are determined depending on the length of the element, as well as on the soil conditions. It has been established that the minimum frequencies are realized for shell modes of vibration with a length parameter of the pipeline section (the ratio of the length of the section to the radius) not exceeding 13. A formula is derived that allows one to determine the boundary between the use of the rod and shell theory for calculating pipelines for dynamic effects. Using the dynamic stability criterion, in which the frequency of natural oscillations vanishes, expressions are derived that allow one to determine the external critical pressure on the wall of the pipeline, which takes into account the length of the pipeline, as well as the number of half waves in the transverse and longitudinal directions, in which the pipeline goes into emergency condition.

scholarly journals Evaluation of stresses in large diameter, thin walled piping at support locations

1992 ◽  
Author(s):  
B.J. Bryan ◽  
H.E. Jr. Flanders ◽  
G.B. Jr. Rawls
Keyword(s):  
Large Diameter ◽  
Thin Walled

scholarly journals Dynamic Impedances of Offshore Rock-Socketed Monopiles

2019 ◽  
Vol 7 (5) ◽  
pp. 134 ◽  
Author(s):  
Rui He ◽  
Ji Ji ◽  
Jisheng Zhang ◽  
Wei Peng ◽  
Zufeng Sun ◽  
...  
Keyword(s):  
Numerical Model ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Dynamic Stiffness ◽  
Large Diameter ◽  
Offshore Wind ◽  
Offshore Wind Turbines ◽  
Thin Walled ◽  
Rock Parameters ◽  
Radiative Damping

With the development of offshore wind energy in China, more and more offshore wind turbines are being constructed in rock-based sea areas. However, the large diameter and thin-walled steel rock-socketed monopiles are very scarce at present, and both the construction and design are very difficult. For the design, the dynamic safety during the whole lifetime of the wind turbine is difficult to guarantee. Dynamic safety of a turbine is mostly controlled by the dynamic impedances of the rock-socketed monopile, which are still not well understood. How to choose the appropriate impedances of the socketed monopiles so that the wind turbines will neither resonant nor be too conservative is the main problem. Based on a numerical model in this study, the accurate impedances are obtained for different frequencies of excitation, different soil and rock parameters, and different rock-socketed lengths. The dynamic stiffness of monopile increases, while the radiative damping decreases as rock-socketed depth increases. When the weathering degree of rock increases, the dynamic stiffness of the monopile decreases, while the radiative damping increases.

Dynamic Stability Response of Piggyback Pipelines

2010 ◽  
Author(s):  
Hammam Zeitoun ◽  
Masˇa Brankovic´ ◽  
Knut To̸rnes ◽  
Simon Wong ◽  
Eve Hollingsworth ◽  
...  
Keyword(s):  
Stability Analysis ◽  
Dynamic Response ◽  
Dynamic Stability ◽  
Large Diameter ◽  
Hydrodynamic Forces ◽  
Model Testing ◽  
Equivalent Diameter ◽  
Pipeline System ◽  
Hydrodynamic Coefficients ◽  
Hydrodynamic Loads

One of the main aspects of subsea pipeline design is ensuring pipeline stability on the seabed under the action of hydrodynamic loads. Hydrodynamic loads acting on Piggyback Pipeline Systems have traditionally been determined by pipeline engineers using an ‘equivalent pipeline diameter’ approach. The approach is simple and assumes that hydrodynamic loads on the Piggyback Pipeline System are equal to the loads on a single pipeline with diameter equal to the projected height of the piggyback bundle (the sum of the large diameter pipeline, small diameter pipeline and gap between the pipelines) [1]. Hydrodynamic coefficients for single pipelines are used in combination with the ‘equivalent diameter pipe’ to determine the hydrodynamic loads on the Piggyback Pipeline System. In order to assess more accurately the dynamic response of a Piggyback Pipeline System, an extensive set of physical model tests has been performed to measure hydrodynamic forces on a Piggyback Pipeline System in combined waves and currents conditions, and to determine in-line and lift force coefficients which can be used in a dynamic stability analysis to generate the hydrodynamic forces on the pipeline [2]. This paper describes the implementation of the model testing results in finite elements dynamic stability analysis and presents a case study where the dynamic response of a Piggyback Pipeline System was assessed using both the conventional ‘equivalent diameter approach’ and the hydrodynamic coefficients determined using model testing. The responses predicted using both approaches were compared and key findings presented in the paper, in terms of adequacy of the equivalent diameter approach, and effect of piggyback gap (separation between the main line and the secondary line) on the response.

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