Global In-Place System Behavior of Flexible Pipeline on Seabed

2015 ◽  
Author(s):  
Maša Brankovic ◽  
Stian Vervik ◽  
Erik Løken ◽  
Per Damsleth
Keyword(s):  
System Design ◽  
Failure Modes ◽  
Compressive Force ◽  
Pipeline System ◽  
Fe Model ◽  
Functional Requirements ◽  
Flexible Pipe ◽  
Axial Compressive Force ◽  
Global Buckling ◽  
Design Requirements

A pipeline system consists of the flexible pipe and all associated ancillary components up to the connecting components at battery limits. The global system design deals with aspects related to the overall flexible pipe system — not cross-section or component design. Key system design issues to address are specified in ISO 13628-11:2007 (API 17B) and include general system design requirements, flowline design requirements, and interfaces involving different contractors and suppliers. Unlike unbonded flexible risers that operate in tension, flexible pipe laying on the seabed will be subject to compressive forces and global buckling as for rigid pipelines. The global flexible pipeline system design will use relevant design codes such as ISO 13628-11:2007 and API 17B / 17J. Yet, the terminology and what such design encompasses can be interpreted differently amongst the community of flexible designers, installers and operators. Failure modes, for example, are not perceived in the same way. While axial compressive force may not be allowed for a riser design, it is a normal flexible pipe response to expansion when pressurized on the seabed. Pull-in and connection forces and moments may be perceived as maximum loads by installers and subsea equipment suppliers but the pressure-induced hydrotest and operational loads may exceed these and overstress the piping leading to a HISC failure. The system functional requirements for flexible pipelines are similar to rigid lines but when it comes to a flowline laid on the seabed, exposed to pressure and temperature, the methodology for establishing accurate predictable global behaviour is still under development in the industry. To perform the global in-place design of a flexible flowline, a detailed understanding of the effects of pressure and temperature on the unbonded flexible construction with respect to its bending stiffness and expansion and the limiting criteria stipulated by the manufacturer is needed. The flexible’s behaviour can be simulated using a 3D FE model capturing the effects of seabed surface variations, interaction with soil, and entire load history from installation, to flooding and hydrotest to filling with product at a range of pressures and temperatures including start-up shut-down cycles. Whereas general requirements are stipulated in API 17, specific guidelines applicable to global buckling design are found in DNV-RP-F110 for rigid pipelines. This predictive analysis methodology using risk-based design criteria provides the basis for a robust design that can accommodate large variations in installation tolerances, uneven seabed, varying soils, etc., while providing all concerned with a sound understanding of the flexible behavior and interface loads throughout its design life.

Smart Home System Design Based on Internet of Things

2014 ◽  
Vol 602-605 ◽  
pp. 3808-3812 ◽  
Author(s):  
Zhen Wang
Keyword(s):  
Internet Of Things ◽  
System Design ◽  
Smart Home ◽  
Development Trend ◽  
Functional Requirements ◽  
Key Technology ◽  
Key Technologies ◽  
Embedded Processing ◽  
Design Requirements ◽  
Household System

As sensor, semiconductor, embedded processing, such as the development of technology, smart home system is more and more get people's attention, make household intelligent has become a development trend. This paper analyzes the key technologies of Internet of things intelligent household the functional requirements, and the key technology of Internet of things intelligent household, expounds the principle and design requirements of the system, on this basis, design a set of relatively complete Internet of things intelligent household system. The smart home system designed in this paper can realize monitoring, alarm, control and reflect the intelligent household convenience and practicability, has wide application prospect.

An Experimental and Numerical Study on the Axial Compression Response of Flexible Pipes

2010 ◽  
Author(s):  
Jose´ Renato M. de Sousa ◽  
Paula F. Viero ◽  
Carlos Magluta ◽  
Ney Roitman
Keyword(s):  
Axial Compression ◽  
Failure Modes ◽  
Mechanical Response ◽  
Numerical Study ◽  
Three Dimensional ◽  
Experimental Tests ◽  
Mechanical Analysis ◽  
Fe Model ◽  
Flexible Pipe ◽  
Flexible Pipes

This paper deals with a nonlinear three-dimensional finite element (FE) model capable of predicting the mechanical response of flexible pipes subjected to axisymmetric loads focusing on their axial compression response. Moreover, in order to validate this model, experimental tests carried out at COPPE/UFRJ are also described. In these tests, a typical 4″ flexible pipe was subjected to axial compression until its failure is reached. Radial and axial displacements were measured and compared to the model predictions. The good agreement between all obtained results points that the proposed FE model is efficient to estimate the response of flexible pipes to axial compression and, furthermore, has potential to be employed in the identification of the failure modes related to excessive axial compression as well as in the mechanical analysis of flexible pipes under other types of loads.

An Experimental and Numerical Study on the Axial Compression Response of Flexible Pipes

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
José Renato M. de Sousa ◽  
Paula F. Viero ◽  
Carlos Magluta ◽  
Ney Roitman
Keyword(s):  
Axial Compression ◽  
Failure Modes ◽  
Mechanical Response ◽  
Numerical Study ◽  
Three Dimensional ◽  
Experimental Tests ◽  
Mechanical Analysis ◽  
Fe Model ◽  
Flexible Pipe ◽  
Flexible Pipes

This paper deals with a nonlinear three-dimensional finite element (FE) model capable of predicting the mechanical response of flexible pipes subjected to axisymmetric loads focusing on their axial compression response. Moreover, in order to validate this model, experimental tests are also described. In these tests, a typical 4 in. flexible pipe was subjected to axial compression until its failure is reached. Radial and axial displacements were measured and compared to the model predictions. The good agreement between all results points out that the proposed FE model is effective to estimate the response of flexible pipes to axial compression and; furthermore, has potential to be employed in the identification of the failure modes related to excessive axial compression as well as in the mechanical analysis of flexible pipes under other types of loads.

Global Buckling Assessment of High Pressure and High Temperature (HP/HT) Offshore Pipeline

2010 ◽  
Author(s):  
Seung-Ho Yang ◽  
Jong-Jin Jung ◽  
Yun-Hak Kim ◽  
Woo-Seob Lee ◽  
Jong-Bae Kim
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Pipeline System ◽  
Fe Model ◽  
Offshore Pipelines ◽  
Buckling Behavior ◽  
High Pressure High Temperature ◽  
Offshore Pipeline ◽  
Global Buckling ◽  
The Stability

In recent years, requirement for the consideration of global buckling due to high pressure/high temperature (HP/HT) condition has increased in the detailed design of offshore pipelines on a seabed. The interaction between pipeline and seabed including support structures or sleepers gives a significant effect on buckling behavior. Global lateral buckling analysis has been carried out to assess the stability of offshore HP/HT pipelines considering the interaction between HP/HT submarine pipeline system/foundation structure and seabed. A non-linear finite element method is used in the present static analysis using the ABAQUS program. The FE model considers concrete sleepers as well as 3-D profile of the seabed. The stress distribution and lateral amplitude of the pipeline were evaluated and remedial measures were suggested to ensure that pipe stresses and strains are kept within allowable limits. Sleepers are designed as a buckle trigger which can provide artificial imperfection to allow pipe to move laterally and mitigate axial force. Comparative study could provide design strategy of pipeline related to sleeper supports.

scholarly journals Numerical Modeling and Safety Design for Lithium-Ion Vehicle Battery Modules Subject to Crush Loading

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 118
Author(s):  
Feng Zhu ◽  
Runzhou Zhou ◽  
David J. Sypeck
Keyword(s):  
Failure Modes ◽  
Computational Study ◽  
Short Circuit ◽  
Computational Cost ◽  
Lithium Ion ◽  
Simplified Model ◽  
Homogeneous Material ◽  
Fe Model ◽  
Safety Design ◽  
Battery Module

In this work, a computational study was carried out to simulate crushing tests on lithium-ion vehicle battery modules. The tests were performed on commercial battery modules subject to wedge cutting at low speeds. Based on loading and boundary conditions in the tests, finite element (FE) models were developed using explicit FEA code LS-DYNA. The model predictions demonstrated a good agreement in terms of structural failure modes and force–displacement responses at both cell and module levels. The model was extended to study additional loading conditions such as indentation by a cylinder and a rectangular block. The effect of other module components such as the cover and cooling plates was analyzed, and the results have the potential for improving battery module safety design. Based on the detailed FE model, to reduce its computational cost, a simplified model was developed by representing the battery module with a homogeneous material law. Then, all three scenarios were simulated, and the results show that this simplified model can reasonably predict the short circuit initiation of the battery module.

scholarly journals Design and analysis of concrete-filled tubular flange girders under combined loading

2021 ◽  
pp. 136943322110015
Author(s):  
Rana Al-Dujele ◽  
Katherine Ann Cashell
Keyword(s):  
Finite Element ◽  
Axial Force ◽  
Failure Modes ◽  
Numerical Study ◽  
Combined Loading ◽  
Torsional Stiffness ◽  
Fe Model ◽  
Combined Effects ◽  
Element Analysis ◽  
Hollow Section

This paper is concerned with the behaviour of concrete-filled tubular flange girders (CFTFGs) under the combination of bending and tensile axial force. CFTFG is a relatively new structural solution comprising a steel beam in which the compression flange plate is replaced with a concrete-filled hollow section to create an efficient and effective load-carrying solution. These members have very high torsional stiffness and lateral torsional buckling strength in comparison with conventional steel I-girders of similar depth, width and steel weight and are there-fore capable of carrying very heavy loads over long spans. Current design codes do not explicitly include guidance for the design of these members, which are asymmetric in nature under the combined effects of tension and bending. The current paper presents a numerical study into the behaviour of CFTFGs under the combined effects of positive bending and axial tension. The study includes different loading combinations and the associated failure modes are identified and discussed. To facilitate this study, a finite element (FE) model is developed using the ABAQUS software which is capable of capturing both the geometric and material nonlinearities of the behaviour. Based on the results of finite element analysis, the moment–axial force interaction relationship is presented and a simplified equation is proposed for the design of CFTFGs under combined bending and tensile axial force.

scholarly journals Instability analysis of a filament-wound composite tube subjected to compression/bending

2019 ◽  
Vol 28 ◽  
pp. 096369351987741
Author(s):  
Gyula Szabó ◽  
Károly Váradi
Keyword(s):  
Failure Modes ◽  
Slenderness Ratio ◽  
Equivalent Stress ◽  
Bending Test ◽  
Test Machine ◽  
Fe Model ◽  
Rubber Tube ◽  
Nonlinear Buckling ◽  
Cross Sectional ◽  
Composite Tube

The aim of this study is to investigate the global buckling of a relatively long composite cord–rubber tube subjected to axial compression and its cross-sectional instability due to bending by a macromechanical nonlinear finite element (FE) model (nonlinear buckling analysis). Composite reinforcement layers are modelled as transversely isotropic ones, while elastomer liners are described by a hyperelastic material model that assumes incompressibility. Force–displacement, equivalent strain, equivalent stress results along with oblateness and curvature results for the complete process have been presented. It is justified that bending leads to ovalization of the cross section and results in a loss of the load-carrying capacity of the tube. Strain states in reinforcement layers have been presented, which imply that the probable failure modes of the reinforcement layers are both delamination and yarn-matrix debonding. There is a significant increase in strains due to cross-sectional instability, which proves that the effect of cross-sectional instability on material behaviour of the tube is crucial. A parametric analysis has been performed to investigate the effect of the member slenderness ratio on cross-sectional instability of the composite tube. It shows that Brazier force is inversely proportional to the slenderness ratio. It further shows that higher oblateness parameters occur in case of a lower slenderness ratio and that cross-sectional instability takes place at a lower dimensionless displacement in case of a lower slenderness ratio. FE results have been validated by a compression/bending test experiment conducted on a tensile test machine.

Fire and Post-Fire Performance of Space Grid Structures

2012 ◽  
Vol 238 ◽  
pp. 621-624 ◽  
Author(s):  
Guang Yong Wang ◽  
Xing Qiang Wang ◽  
Guang Wei Liu
Keyword(s):  
Finite Element ◽  
Failure Modes ◽  
Fe Model ◽  
Fire Damage ◽  
Fire Performance ◽  
Membrane Action ◽  
Load Bearing Capacity ◽  
Space Grid ◽  
Deformation Stress ◽  
In Fire

A fire performance finite element (FE) model of space grid structures in fire and after fire is proposed, and deformation, stress redistribution, failure modes of grid structures are also studied. The result shows that tensile membrane action arises when the grid is loaded after fire, and the load bearing capacity after fire is reduced by fire damage.

scholarly journals Failure modes and reliability oriented system design for aerospace power electronic converters

2020 ◽  
pp. 1-1
Author(s):  
Jayakrishnan Harikumaran ◽  
Giovanni Migliazza ◽  
Giampaolo Buticchi ◽  
Vincenzo Madonna ◽  
Paolo Giangrande ◽  
...  
Keyword(s):  
System Design ◽  
Failure Modes ◽  
Power Electronic ◽  
Power Electronic Converters ◽  
Oriented System

scholarly journals Edgewise Compressive Behavior of Composite Structural Insulated Panels with Magnesium Oxide Board Facings

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3030
Author(s):  
Łukasz Smakosz ◽  
Ireneusz Kreja ◽  
Zbigniew Pozorski
Keyword(s):  
Magnesium Oxide ◽  
Sandwich Panel ◽  
Failure Modes ◽  
Small Scale ◽  
Fe Model ◽  
Compressive Behavior ◽  
Axial Loads ◽  
Reliable Prediction ◽  
Structural Insulated Panels ◽  
Prediction Capability

Edgewise compression response of a composite structural insulated panel (CSIP) with magnesium oxide board facings was investigated. The discussed CSIP is a novel multifunctional sandwich panel introduced to the housing industry as a part of the wall, floor, and roof assemblies. The study aims to propose a computational tool for reliable prediction of failure modes of CSIPs subjected to concentric and eccentric axial loads. An advanced numerical model was proposed that includes geometrical and material nonlinearity as well as incorporates the material bimodularity effect to achieve accurate and versatile failure mode prediction capability. Laboratory tests on small-scale CSIP samples of three different slenderness ratios and full-scale panels loaded with three different eccentricity values were carried out, and the test data were compared with numerical results for validation. The finite element (FE) model successfully captured CSIP’s inelastic response in uniaxial compression and when flexural action was introduced by eccentric loads or buckling and predicted all failure modes correctly. The comprehensive validation showed that the proposed approach could be considered a robust and versatile aid in CSIP design.

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