Further Advances on Concrete Coating Impact on Pipeline Strength

2017 ◽  
Author(s):  
Alberto Battistini ◽  
Luca Catena ◽  
Adelina Mancini ◽  
Lorenzo Marchionni ◽  
Antonio Parrella ◽  
...  
Keyword(s):  
Mechanical Behavior ◽  
Damage Evolution ◽  
Bending Stiffness ◽  
The State ◽  
Fe Model ◽  
Deformation Capacity ◽  
Strain Concentration ◽  
Concrete Damage ◽  
Strength And Deformation ◽  
Concrete Coating

Concrete Weight Coating is used in offshore industry to provide for pipeline vertical and lateral stability against waves and currents and to guarantee protection against fishing activities. Reinforced concrete coating of adequate strength, especially in case of thick coatings for stringent in-place stability requirements, entails additional bending stiffness and consequently strain concentration at field joints, thus significantly affecting the state of stress and strain on the pipe steel during laying firstly, and then during operations. Attention of the offshore pipeline industry has been focused in the development of experimental and theoretical activities in a more scientific way, which aimed to satisfy the need of a better knowledge in this field. Both analytical and FEM solutions are available in the free literature and relevant standards to predict the contribution of concrete coating layer on global pipeline strength and deformation capacity and simplified threshold values for the concrete damage are provided, as well. Generally, for installation analysis purpose, a pipeline with equivalent mechanical behavior (bending moment-curvature relationship) and physical (weight) properties is used in installation and operation analyses. No assumptions are typically made on concrete damage evolution to evaluate the decay of pipe capacity beyond the elastic range. In this paper new advances in modelling the mechanical behavior of concrete coated joints are discussed. In particular an advanced ABAQUS finite element model is proposed to take into account the effect of concrete coating damage on the overall capacity. The following effects have been accounted: • Non-linear stress-strain relationship of the steel at large usage factors/curvatures on the strain concentration at the field joint. • Concrete coating damage evolution on global pipeline bending stiffness. In this paper: • The state-of-the-art about published materials, numerical studies and design approaches on concrete material modelling and concrete coated pipes is briefly presented; • A FEM based analysis methodology is drawn and proposed for the strength and deformation capacity assessment of a concrete coated pipe; • The FEM model is calibrated on available full scale tests; • The results of a project case study performed with ABAQUS FE Model are given.

Strength and Deformation Capacity of Corroded Pipes: The Joint Industry Project

2013 ◽  
Author(s):  
Erik Levold ◽  
Andrea Restelli ◽  
Lorenzo Marchionni ◽  
Caterina Molinari ◽  
Luigino Vitali
Keyword(s):  
Failure Modes ◽  
State Of The Art ◽  
Local Buckling ◽  
Bending Moment ◽  
External Pressure ◽  
Fe Model ◽  
Deformation Capacity ◽  
Offshore Pipelines ◽  
Strength And Deformation ◽  
Bending Loading

Considering the future development for offshore pipelines, moving towards difficult operating condition and deep/ultra-deep water applications, there is the need to understand the failure mechanisms and better quantify the strength and deformation capacity of corroded pipelines considering the relevant failure modes (collapse, local buckling under internal and external pressure, fracture / plastic collapse etc.). A Joint Industry Project sponsored by ENI E&P and Statoil has been launched with the objective to quantify and assess the strength and deformation capacity of corroded pipes in presence of internal overpressure and axial/bending loading. In this paper: • The State-of-the-Art on strength and deformation capacity of corroded pipes is presented; • The full-scale laboratory tests on corroded pipes under bending moment dominated load conditions, performed at C-FER facilities, are shown together with the calibrated ABAQUS FE Model; • The results of the ABAQUS FEM parametric study are presented.

Pipe Strength and Deformation Capacity: A Novel FE Tool for the Numerical Lab

2014 ◽  
Author(s):  
Lorenzo Maria Bartolini ◽  
Alberto Battistini ◽  
Lorenzo Marchionni ◽  
Antonio Parrella ◽  
Maurizio Spinazzè ◽  
...  
Keyword(s):  
Deep Water ◽  
Fem Analysis ◽  
Fe Model ◽  
Deformation Capacity ◽  
Mechanical Behaviors ◽  
Offshore Pipelines ◽  
Local Characteristics ◽  
Strength And Deformation ◽  
Global And Local ◽  
Buckle Arrestors

Future offshore pipelines development moves towards challenging operating condition and deep/ultra-deep water applications. Understanding the failure mechanisms and quantifying the strength and deformation capacity of pipelines, special components (buckle arrestors, wye, etc.) and in-line structures (in-line sled, in-line valve, in-line tee, etc.) is a need, under installation and operation loads, taking in account different geometrical characteristics and mechanical behaviors. The objective of this paper is to present and discuss recent FEM approaches integrating global and local analyses to evaluate the pipeline response and local effects, respectively. Thanks to this method the results coming from the global FEM analysis (main loads and driving phenomena) are used as input data for local FE Model with the aim to detect stress/strain intensification and other issues due to the local characteristics. In this paper: • The challenges of future deep water offshore pipelines are briefly presented; • The typical loading scenarios for pipelines during installation and operation are discussed; • The PipeONE 2014 tool, developed to facilitate the input/output data sharing between global and local FEM analyses, is presented and fully described in its main characteristics and capabilities; • An example is presented with the aim to understand and to appreciate the PipeONE 2014 functionality in FE modeling.

Finite Element Analysis of Strain Concentration in Field Joint of Concrete Coated Pipelines

2009 ◽  
Author(s):  
Nikzad Nourpanah ◽  
Farid Taheri
Keyword(s):  
Finite Element ◽  
General Purpose ◽  
Longitudinal Distribution ◽  
Shear Stresses ◽  
Fe Model ◽  
Test Results ◽  
Element Analysis ◽  
Strain Concentration ◽  
Constant Shear Stress ◽  
Concrete Coating

Realistic and accurate modeling of the strains developed in concrete coated pipelines is an important objective to offshore pipeline industry. This is because of the acceptance of the strain-based design methods and also the increasing demand on pipelines to operate under harsher environments/loading conditions. The problem has several sources of nonlinearity, namely: material plasticity, concrete cracking and crushing and concrete slippage on the steel pipe. In this paper, a framework and procedure for finite element (FE) modeling of concrete coated pipelines is presented and verified against test results available in literature. The mechanics of strain concentration at the Field Joint (FJ), where the coating has an abrupt discontinuity is described and studied via the verified FE model. These aspects are all described and modeled appropriately using the general purpose FE software ABAQUS, resulting in a realistic and accurate FE model which predicts the strain and stress distribution in the steel, concrete coating and the anticorrosion layer. Output results, presented in the form of variation of moment versus strain, longitudinal distribution of the axial strains, the maximum FJ strains, strain concentration factor as a function of global strain and relative slippage of concrete coating are reported and verified with comparison to test data. Good agreements, both in trend and also quantities are observed, thereby verifying the integrity of the framework suited for the further development, which would include a parametric study with the aim of developing practical design equations. Discussion on the circumferential distribution of shear stresses in the anticorrosion layer is also presented. FE results show a constant shear stress distributed nearly all along the circumference, in concert with the test results.

In-Place FE Modeling of Unbonded Flexible Pipelines Capturing Pressure Stiffening and Decoupled Axial/Nonlinear Bending Stiffness

2010 ◽  
Author(s):  
Edvin Hanken ◽  
Evelyn R. Hollingsworth ◽  
Lars S. Fagerland
Keyword(s):  
Water Injection ◽  
Bending Stiffness ◽  
Axial Stiffness ◽  
Fe Model ◽  
Nonlinear Bending ◽  
Upheaval Buckling ◽  
History Effects ◽  
System Integrity ◽  
Non Linear ◽  
Bending Behaviour

For fast track pipeline projects the need for costly installation vessels and sophisticated materials for rigid pipeline water injection systems, have made flexible pipelines a competitive alternative. They can be installed with less costly construction vessels, provide a competitive lead time and a corrosion resistant compliant material. Flexible pipelines have relative high axial stiffness and low non-linear bending stiffness which is a challenge to model correctly with FE for in-place analyses of pipelines. Whilst some FE programs can model the non-linear bending behaviour of a flexible pipeline at a given pressure, current FE tools do not include the effect of increased bending resistance as the system is pressurized. Therefore, a 3D FE model in ANSYS was developed to simulate the decoupled axial and nonlinear bending behaviour of a flexible, including the bend stiffening effect for increasing pressure. A description of the model is given in this paper. It will be demonstrated how the FE model can be used to simulate the 3D nonlinear catenary behaviour of an high pressure flexible pipeline tied into a manifold during pressurization. Due to high manifold hub loads during pressurization it is essential that such a model is capable of capturing all effects during pressurization to achieve an acceptable confidence level of the system integrity. It is also described how the FE model is used for upheaval buckling design, capturing non-linearities and load history effects that can reduce the conservatism in the design.

Effect of Detailed Formations on the In-Plane Shear Capacity of Hairpin Connectors in Precast RC Floor Slabs

2010 ◽  
Vol 163-167 ◽  
pp. 1510-1514 ◽  
Author(s):  
Rui Pang ◽  
Shu Ting Liang ◽  
Xiao Jun Zhu ◽  
Yao Meng
Keyword(s):  
Simulation Analysis ◽  
Plate Thickness ◽  
Shear Capacity ◽  
Steel Plates ◽  
Strong Impact ◽  
Deformation Capacity ◽  
Initial Stiffness ◽  
Plane Shear ◽  
Floor Slabs ◽  
Strength And Deformation

Detailed formation of precast floor slab connectors has significant effect on their shear capacity, but there is no such specific provision on it at present. The effects of detailed formations on the shear strength, stiffness and deformation capacity of hairpin connectors(HPC) were studied, through numerical simulation analysis under in-plane shear force. The imbedded depth (d), slug length (h), steel plate thickness (t) and its stickout(s) were taken as parameters. The analysis results show that: ⅰ) the increase of imbedded depth can improve the bearing capacity and stiffness of HPC, but decrease the deformation capacity; ⅱ) with the increase of slug length, the HPC strength, stiffness and deformation capacity raised a lot; ⅲ) the steel plates’ thickness has small effect on the stiffness, but has strong impact on the strength and deformation capacity of HPC. ⅳ) the stickout can affect the initial stiffness and yield strength of HPC slightly, but has a considerable impact on its ultimate strength and deformation capacity. On the basis of analysis, recommendations on formation details of HPC are proposed for design and construction.

Experimental investigation of seismic performance of a novel isostatic frame-cladding system

2022 ◽  
pp. 136943322110572
Author(s):  
Xun Chong ◽  
Pu Huo ◽  
Linlin Xie ◽  
Qing Jiang ◽  
Linbing Hou ◽  
...  
Keyword(s):  
Seismic Performance ◽  
Damage Evolution ◽  
Failure Modes ◽  
Static Load ◽  
Precast Concrete ◽  
Frame Structure ◽  
Deformation Capacity ◽  
Load Bearing Capacity ◽  
Cladding Panels ◽  
Energy Dissipation Capacity

A new connection measure between the precast concrete (PC) cladding panel and PC frame structure is proposed to realize a new kind of isostatic frame-cladding system. Three full-scale PC wall-frame substructures were tested under the quasi-static load. These substructures included a bare wall-frame specimen, a specimen with a cladding panel that has no opening, and a specimen with a cladding panel that has an opening in it. The damage evolution, failure mode, load-bearing capacity, deformation capacity, and energy dissipation capacity of three specimens were compared. The results indicated that the motions of the cladding panels and the main structures were uncoupled through the relative clearance of the bottom connections, and three specimens exhibited approximately identical failure modes and seismic performance. Thus, the reliability of this new isostatic system was validated.

scholarly journals Performance of Steel Pipeline with Concrete Coating (Modeled with Concrete Damage Plasticity) Underseismic Wave Passage

2013 ◽  
Vol 459 ◽  
pp. 608-613 ◽  
Author(s):  
Joanna M. Dulinska ◽  
Dorota Jasinska
Keyword(s):  
Seismic Analysis ◽  
Seismic Zone ◽  
Ground Acceleration ◽  
Steel Pipeline ◽  
Ground Deformations ◽  
Inelastic Behaviour ◽  
Concrete Damage ◽  
Concrete Coating ◽  
Wave Passage ◽  
Tensile Damage

The paper presents the analysis of the dynamic response of a steel pipeline with concrete coating to a real earthquakeregistered in central Poland in 2012. The peak ground acceleration of the shock was scaled up to maximal values predicted for this seismic zone. To represent theinelastic behavior of the material of the concrete coating under dynamic loading, the concrete damaged plasticity constitutive model was assumed.The modelallows to describeplastic strains and irreversible tensile and compression damage that occurs during the cracking process.For seismic analysis two models (uniform and non-uniform) of kinematic excitation were applied. In the modelof uniform excitation it was assumed that the motion of all supports was identical. Inthe model of non-uniform excitation, typical for long structures, the wave passage along the pipelinewith different velocities (500, 400 and 300 m/s) was taken into account. It occurred that for the model of uniform excitation the concrete material of the coating remained elastic with no tensile damage. For the model of non-uniform excitation, inelastic behaviour of the coating was observed. The plastic strain areas appeared above all supports. The tensile damage (cracking) wasalso noticed in these areas: the lower wave velocity was assumed, the greater area of concrete coating was affected by plastic strains and tensile damage (cracking). It was the consequence of the quasi-static effects which resulted from ground deformations imposed on the pipeline during the seismic shock.

Two-Way Coupled Multiscale Model for Predicting Mechanical Behavior of Bone Subjected to Viscoelastic Deformation and Fracture Damage

2017 ◽  
Vol 139 (2) ◽  
Author(s):  
Taesun You ◽  
Yong-Rak Kim ◽  
Taehyo Park
Keyword(s):  
Mechanical Behavior ◽  
Material Properties ◽  
Damage Evolution ◽  
Multiscale Model ◽  
Local Scale ◽  
Viscoelastic Deformation ◽  
Rate Dependent ◽  
Deformation And Fracture ◽  
Evolution Characteristics ◽  
Fracture Damage

This paper presents a two-way linked computational multiscale model and its application to predict the mechanical behavior of bone subjected to viscoelastic deformation and fracture damage. The model is based on continuum thermos-mechanics and is implemented through the finite element method (FEM). Two physical length scales (the global scale of bone and local scale of compact bone) were two-way coupled in the framework by linking a homogenized global object to heterogeneous local-scale representative volume elements (RVEs). Multiscaling accounts for microstructure heterogeneity, viscoelastic deformation, and rate-dependent fracture damage at the local scale in order to predict the overall behavior of bone by using a viscoelastic cohesive zone model incorporated with a rate-dependent damage evolution law. In particular, age-related changes in material properties and geometries in bone were considered to investigate the effect of aging, loading rate, and damage evolution characteristics on the mechanical behavior of bone. The model successfully demonstrated its capability to predict the viscoelastic response and fracture damage due to different levels of aging, loading conditions (such as rates), and microscale damage evolution characteristics with only material properties of each constituent in the RVEs.

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