Dynamic Simulation of Free-Spanning Pipeline Trawl Board Pull-Over

2011 ◽  
Author(s):  
Vegard Longva ◽  
Svein Sævik ◽  
Erik Levold ◽  
Ha˚var Ilstad ◽  
Per Teigen
Keyword(s):  
Finite Element ◽  
Forward Speed ◽  
Finite Element Analyses ◽  
Analysis Method ◽  
Hydrodynamic Load ◽  
Drag Coefficients ◽  
Load Model ◽  
Dynamic Mass ◽  
Hydrodynamic Loading ◽  
Heading Angle

The main objective of this effort was to examine if finite element analyses can be used to predict pull-over loads from a trawl board. Here the trawl board was represented by a 6-DOF hydro-dynamic load model, where the mass and drag coefficients are expressed as functions of seabed gap, seabed inclination angle and heading angle. Both seabed proximity and forward-speed effects of the trawl board are hence included. The applied drag coefficients were established by model testing, while the hydro-dynamic mass was found by potential theory calculations. Compared to previous efforts, the hydrodynamic loading on the trawl board is represented in a far more consistent way in this paper. A simulation model which contained a polyvalent trawl board and a free-spanning pipeline was established. Several simulations were performed with span heights between 0 m and 2 m. In all simulations the pull-over force and pipeline response was sampled. The sampled results were thereafter validated by means of the analysis method and pull-over loading proposed in the DNV-RP-F111 code. Some differences could be observed in the response histories, but in summary the numerical model predicts a realistic pull-over. This indicates that the applied hydrodynamic load model captures the relevant effects during the pullover.

Effect of Material Stress-Strain Behavior and Pipe Geometry on the Deformability of High-Grade Pipelines

2004 ◽  
Vol 126 (1) ◽  
pp. 113-119 ◽  
Author(s):  
Hiroshi Yatabe ◽  
Naoki Fukuda ◽  
Tomoki Masuda ◽  
Masao Toyoda
Keyword(s):  
Finite Element ◽  
High Grade ◽  
Finite Element Analyses ◽  
Analysis Method ◽  
Element Analysis ◽  
Line Pipe ◽  
Strain Behavior ◽  
Parametric Studies ◽  
Pipe Geometry ◽  
Strain Hardening Behavior

In this study, the deformability of high-grade pipelines subjected to an axial compressive deformation was experimentally and analytically discussed. Six cases of axial compression experiments with high-grade line pipe were carried out. The pipe specimens had various material properties and wall thickness. Finite-element analyses were also carried out and verified the reliability. Then, a finite-element analysis method for evaluating the deformability of the line pipe was established. By using this method, parametric studies were carried out. The effects of the strain-hardening behavior and pipe geometry on the deformability of the high-grade pipelines were examined.

On the Influence From Hydrodynamic Forces on Speed and Footprint for a Falling Riser

2004 ◽  
Author(s):  
Vidar Berntsen ◽  
Carl M. Larsen ◽  
Elizabeth Passano ◽  
Nilo De Moura Jorge ◽  
Jose´ Roberto
Keyword(s):  
Material Model ◽  
Model Material ◽  
Model Parameters ◽  
Analysis Method ◽  
Hydrodynamic Load ◽  
Stochastic Variation ◽  
Dynamic Simulations ◽  
Load Model ◽  
Parameter Variations ◽  
The Impact

This paper presents analysis method and key results from dynamic simulations of a drilling riser on 1900 metres water depth after release of upper end. Key results are the geometry of the collapsed riser on the seafloor (footprint) and the impact speed of the riser when hitting the seafloor. The purpose of the study has been to investigate the influence on the results from operational and model parameters such as vessel offset relative to the riser base, current speed, hydrodynamic load model, material model and interaction between the riser and the seafloor. The main conclusion from the study is that most trends from parameter variations are weak and often overshadowed by a more stochastic variation caused by the inherent complexity of the mechanical behaviour during collapse.

Use of the Finite Element Analysis Method in Pedodontics

2018 ◽  
Vol 55 (4) ◽  
pp. 666-675
Author(s):  
Mihaela Tanase ◽  
Dan Florin Nitoi ◽  
Marina Melescanu Imre ◽  
Dorin Ionescu ◽  
Laura Raducu ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Structural Model ◽  
Analysis Method ◽  
Ansys Software ◽  
Concentrated Force ◽  
Element Analysis ◽  
Finite Element Analysis Method ◽  
The Finite Element Analysis ◽  
Solid Type

The purpose of this study was to determinate , using the Finite Element Analysis Method, the mechanical stress in a solid body , temporary molar restored with the self-curing GC material. The originality of our study consisted in using an accurate structural model and applying a concentrated force and a uniformly distributed pressure. Molar structure was meshed in a Solid Type 45 and the output data were obtained using the ANSYS software. The practical predictions can be made about the behavior of different restorations materials.

Design of flexure revolute joint based on compliance and stiffness ellipsoids

2021 ◽  
pp. 095441002110169
Author(s):  
Jing Zhang ◽  
Hong-wei Guo ◽  
Juan Wu ◽  
Zi-ming Kou ◽  
Anders Eriksson
Keyword(s):  
Finite Element ◽  
Single Point ◽  
Synthesis Method ◽  
Nonlinear Finite Element ◽  
Finite Element Analyses ◽  
Rotational Stiffness ◽  
Rotational Angle ◽  
Parameterized Model ◽  
Flexure Joints ◽  
Translational Stiffness

In view of the problems of low accuracy, small rotational angle, and large impact caused by flexure joints during the deployment process, an integrated flexure revolute (FR) joint for folding mechanisms was designed. The design was based on the method of compliance and stiffness ellipsoids, using a compliant dyad building block as its flexible unit. Using the single-point synthesis method, the parameterized model of the flexible unit was established to achieve a reasonable allocation of flexibility in different directions. Based on the single-parameter error analysis, two error models were established to evaluate the designed flexure joint. The rotational stiffness, the translational stiffness, and the maximum rotational angle of the joints were analyzed by nonlinear finite element analyses. The rotational angle of one joint can reach 25.5° in one direction. The rotational angle of the series FR joint can achieve 50° in one direction. Experiments on single and series flexure joints were carried out to verify the correctness of the design and analysis of the flexure joint.

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