Lateral Buckling Analysis and ECA for Pipeline With Complex Temperature Profile

2012 ◽  
Author(s):  
Zhengmao Yang ◽  
Yadhavaraj Mageshwaran ◽  
Vijay Kittur ◽  
Gerry Lim ◽  
Hong Kiat Chia
Keyword(s):  
High Strain ◽  
Large Strain ◽  
Buckling Analysis ◽  
Large Strains ◽  
Operating Environment ◽  
Lateral Buckling ◽  
Service Environment ◽  
Buckling Behavior ◽  
Complex Temperature ◽  
Sour Service

Lateral buckling analysis of a 32 inch export pipeline operating under high temperature and high pressure in sour service environment was evaluated in this paper. In addition Engineering Critical Assessment (ECA) as per DNV-OS-F101 Appendix A was performed to derive flaw acceptance criteria for pipeline girth weld fabrication during installation. Due to the sour operating environment, low fracture toughness and increased fatigue crack growth rate during operation is expected. Consequently stringent tolerable flaw sizes are obtained for the pipeline sections subject to large strain arising from lateral buckling. In order to improve the reliability of the design and constructability of the pipeline, sleepers will be used to introduce vertical imperfections and initiate buckles at selected locations. In undertaking this it can be illustrated that all the potential lateral buckles are predetermined and pipeline sections with large strains are identified. The stringent tolerable flaw criteria from ECA are applied only on the identified high strain sections. In this paper the design of sleepers and the influence of these additional sleepers on the lateral buckling behavior are investigated.

Fracture Toughness Testing and Validation of Pipeline Girth Weld Flaw Acceptance Criteria for Sour Service Under Large Strain

2011 ◽  
Author(s):  
You You Wu ◽  
Wen Guo Yuan ◽  
Tse Ven Steven Chong ◽  
Jens P. Tronskar
Keyword(s):  
Fracture Toughness ◽  
Oil And Gas ◽  
Large Strain ◽  
Axial Strain ◽  
Laboratory Data ◽  
Local Buckling ◽  
Acceptance Criteria ◽  
Service Environment ◽  
Girth Welds ◽  
Sour Service

Fracture toughness is one of the most important input parameters for assessment of pipeline girth weld failure capacity. For many new subsea pipeline projects there is a need to develop flaw acceptance criteria for pipeline installation considering the operation phase which may involve the transport of sour oil and gas and where the pipeline is exposed to large axial strain due to local buckling. Engineering Critical Assessment (ECA) performed using laboratory data based on conservative KISSC testing gives small acceptable flaw sizes which may be below the workmanship criteria for pipeline laying. DNV has conducted extensive research based on the requirements of DNV-OS-F101 and DNV-RP-F108, aiming to establish a method to develop J-R curves applicable for ECA of pipeline girth welds in sour service environment and a methodology to validate the ECA by segment testing in a laboratory-simulated sour service environment as per DNV-RP-F108.

Initial Testing and Constitutive Modeling of Cellular Rubber Subjected to Large Strains and High Strain Rates

2020 ◽  
Author(s):  
James A. Bieler ◽  
Brad G. Davis
Keyword(s):  
High Strain ◽  
Large Strain ◽  
Constitutive Models ◽  
Cementitious Materials ◽  
Large Strains ◽  
Materials Testing ◽  
Elastic Model ◽  
Strain Rates ◽  
High Strain Rates ◽  
Suitable Material

Abstract In order to allow for the numerical modeling of impacts for the design of live fire facilities commonly used by military and law enforcement personnel against next generation and environmentally friendly ammunition currently in development, constitutive models for novel target materials must be developed. Many existing facilities are constructed from AR500 steel, coupled with a layer of cellular rubber to reduce impact velocities and contain projectile fragments. High strain rate models, such as the commonly used Johnson-Cook constitutive model, are widely available to characterize AR500 steel, but calibrated models do not currently exist to characterize the cellular rubber. This project seeks to address this shortfall and provide a suitable material model for designers of these facilities in order to ensure the safety of users and the public. Appropriate constitutive models that account for the large strain, high strain rates, and temperature effects experienced during ballistic events and the porosity of the material were researched and a plan developed for future materials testing. Three suitable models were selected for further analysis — A Non-Linear Elastic Model described by Johnson in his work with polyurethane coupled with a Mie-Gruneisen equation of state to account for the porosity of the material, an Osborn-Hull model developed for use with crushable solids, and the Holmquist-Johnson-Cook Model commonly used for cementitious materials.

Analytical Solutions for Circular Bars Subjected to Large Strain Plastic Torsion

1990 ◽  
Vol 57 (2) ◽  
pp. 298-306 ◽  
Author(s):  
K. W. Neale ◽  
S. C. Shrivastava
Keyword(s):  
Closed Form ◽  
Analytical Solutions ◽  
Large Strain ◽  
Kinematic Hardening ◽  
Flow Theory ◽  
Constitutive Laws ◽  
Isotropic Hardening ◽  
Large Strains ◽  
Inelastic Behavior ◽  
Rate Dependent

The inelastic behavior of solid circular bars twisted to arbitrarily large strains is considered. Various phenomenological constitutive laws currently employed to model finite strain inelastic behavior are shown to lead to closed-form analytical solutions for torsion. These include rate-independent elastic-plastic isotropic hardening J2 flow theory of plasticity, various kinematic hardening models of flow theory, and both hypoelastic and hyperelastic formulations of J2 deformation theory. Certain rate-dependent inelastic laws, including creep and strain-rate sensitivity models, also permit the development of closed-form solutions. The derivation of these solutions is presented as well as numerous applications to a wide variety of time-independent and rate-dependent plastic constitutive laws.

Lateral buckling behavior and strengthening techniques of coped steel I-beams

2015 ◽  
Vol 108 ◽  
pp. 11-22 ◽  
Author(s):  
Sherif A. Ibrahim ◽  
Abdelrahim K. Dessouki ◽  
Seham A. El -Sa'eed
Keyword(s):  
Lateral Buckling ◽  
Buckling Behavior

The Axisymmetric Deformation of Linearly and Nonlinearly Elastic Spinning Tubes Under End Thrusts and Torques

1998 ◽  
Vol 65 (1) ◽  
pp. 99-106
Author(s):  
T. J. McDevitt ◽  
J. G. Simmonds
Keyword(s):  
Anisotropic Material ◽  
Large Strain ◽  
Axisymmetric Deformation ◽  
Large Strains ◽  
Shells Of Revolution ◽  
Large Rotation ◽  
Elastic Tubes ◽  
Axisymmetric Bending ◽  
Combined Parameters ◽  
Nonlinearly Elastic

We consider the steady-state deformations of elastic tubes spinning steadily and attached in various ways to rigid end plates to which end thrusts and torques are applied. We assume that the tubes are made of homogeneous linearly or nonlinearly anisotropic material and use Simmonds” (1996) simplified dynamic displacement-rotation equations for shells of revolution undergoing large-strain large-rotation axisymmetric bending and torsion. To exploit analytical methods, we confine attention to the nonlinear theory of membranes undergoing small or large strains and the theory of strongly anisotropic tubes suffering small strains. Of particular interest are the boundary layers that appear at each end of the tube, their membrane and bending components, and the penetration of these layers into the tube which, for certain anisotropic materials, may be considerably different from isotropic materials. Remarkably, we find that the behavior of a tube made of a linearly elastic, anisotropic material (having nine elastic parameters) can be described, to a first approximation, by just two combined parameters. The results of the present paper lay the necessary groundwork for a subsequent analysis of the whirling of spinning elastic tubes under end thrusts and torques.

Numerical Modelling of Plastic Deformation and Subsequent Recrystallization in Polycrystalline Materials, Based on a Digital Material Framework

2007 ◽  
Vol 558-559 ◽  
pp. 1133-1138 ◽  
Author(s):  
Roland E. Logé ◽  
M. Bernacki ◽  
H. Resk ◽  
H. Digonnet ◽  
T. Coupez
Keyword(s):  
Level Set ◽  
Large Strain ◽  
Voronoi Tessellation ◽  
Constitutive Law ◽  
Polycrystalline Materials ◽  
Large Strains ◽  
Element Mesh ◽  
Digital Material ◽  
Digital Sample ◽  
Level Set Approach

The development of a digital material framework is presented, allowing to build virtual microstructures in agreement with experimental data. The construction of the virtual material consists in building a multi-level Voronoï tessellation. A polycrystalline microstructure made of grains and sub-grains can be obtained in a random or deterministic way. A corresponding finite element mesh can be generated automatically in 3D, and used for the simulation of mechanical testing under large strain. In the examples shown in this work, the initial mesh was non uniform and anisotropic, taking into account the presence of interfaces between grains and sub-grains. Automatic remeshing was performed due to the large strains, and maintained the non uniform and anisotropic character of the mesh. A level set approach was used to follow the grain boundaries during the deformation. The grain constitutive law was either a viscoplastic power law, or a crystallographic formulation based on crystal plasticity. Stored energies and precise grain boundary network geometries were obtained directly from the deformed digital sample. This information was used for subsequent modelling of grain growth with the level set approach, on the same mesh.

Investigation of Small- to Large-Strain Moduli Correlations of Rockfill Materials – Application to Romaine-2 Dam

2021 ◽  
Author(s):  
Ibrahim Lashin ◽  
Michael Ghali ◽  
Marc Smith ◽  
Daniel Verret ◽  
Mourad Karray
Keyword(s):  
Large Strain ◽  
Deformation Behaviour ◽  
Numerical Data ◽  
Small Strain ◽  
Hyperbolic Model ◽  
Large Strains ◽  
Initial Modulus ◽  
Rockfill Materials ◽  
Materials Used

Establishment of a relationship between the shear wave velocity (Vs) and other geotechnical parameters of rockfill soils at large strains (oedometer modulus, Moedo, tangent modulus, Et) is considered a significant step towards more precise modelling of earth-structure deformation behaviour. In this study, four samples of different gradations, reconstituted from the rockfill materials used in the construction of the Romaine-2 dam, were experimented to correlate the small strain to large strain moduli. Development of Moedo and Vs with consolidation was measured in the laboratory using the piezoelectric ring-actuator technique (P-RAT) incorporated in a large oedometer. Therefore, a correlation between Moedo and small strain shear modulus Go was proposed. Moreover, numerical simulations were performed based on the Duncan-Chang hyperbolic model to correlate the Vs to Duncan-Chang initial modulus(Ei). Based on the experimental and numerical data, a relation between Ei and Vs of the tested rockfill has been established. Verification studies were also carried out on in-situ measurements during Romaine-2 dam construction, proofing the ability of the proposed relationships to predict Ei related to the minor principal stress (σ3) from in-situ Vs measurement. The proposed correlations could help the geotechnical designers to estimate accurately the deformation of rockfill materials from in-situ Vs measurement.

Linear Buckling Analysis Considering No-compression Property of Metal Grid Shells Stiffened by Tension Braces

2021 ◽  
Vol 62 (3) ◽  
pp. 195-205
Author(s):  
Kenji Yamamoto ◽  
Hayato Utebi
Keyword(s):  
Geometrical Nonlinearity ◽  
Buckling Analysis ◽  
Nonlinear Buckling ◽  
Compression Property ◽  
Buckling Behavior ◽  
Metal Grid ◽  
Linear Buckling ◽  
Nonlinear Buckling Analysis ◽  
Linear Buckling Analysis ◽  
Lattice Shells

In order to analyze the buckling behavior of lattice shells stiffened by cables or slender braces without pre-tension, it is necessary to consider the no-compression property of braces. This paper proposes an innovative method of linear buckling analysis that considers the no-compression property of braces. Moreover, in order to examine the proposed method's validity, its results are compared with the results from a nonlinear buckling analysis with geometrical nonlinearity and material nonlinearity to express the no-compression property of braces. The results show that the proposed method can well-predict the buckling behaviors of lattice shells stiffened by tension braces.

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