Numerical Analysis Assessment of the Contact Pressure Between the Flexible Pipe Outer Sheath and the I Tube Interface Equipment for Wearing Research Program

2011 ◽  
Author(s):  
Victor Nogueira ◽  
Fabio Pires ◽  
Fabio Aquino ◽  
Judimar Clevelario ◽  
Terry Sheldrake
Keyword(s):  
Numerical Model ◽  
Contact Pressure ◽  
Research Program ◽  
Dynamic Test ◽  
Test Sample ◽  
Full Scale ◽  
Test Rig ◽  
Flexible Pipe ◽  
Adequate Knowledge ◽  
Outer Sheath

Wellstream is carrying out a research program to provide the adequate knowledge of the interaction between the flexible pipes outer sheath and the I-tube interface equipment used in the field. Wellstream has already completed a full scale dynamic test which was used also to evaluate the wearing behavior of this specific region of the flexible pipe. As a continuation of the mentioned research program Wellstream developed a FEA model of the test rig in order to assess the contact pressure between the flexible pipe outer sheath and the I-tube interface equipment used in the test during the full scale dynamic test. The numerical model used in this assessment was prepared based on the test sample dimensions and test rig characteristics in order to reproduce the actual test condition. Model calibration approach is based on the rigs reaction forces and displacements measured during its execution with strain gauges specially positioned in the test rig’s interest area. This paper introduces the test rig numerical model and presents a comparison between the contact pressure originated by the test loads and the ones expected for the field. Results show that the full scale test contact pressures are significantly higher than the ones expected for the field operation, making the performed test conservative to evaluate the wearing behavior in the field.

PSI Armour Wire for High Collapse Performance of Flexible Pipe

2011 ◽  
Author(s):  
Laurent Paumier ◽  
Olivier Mesnage
Keyword(s):  
Water Depth ◽  
Deep Water ◽  
Production Systems ◽  
Dynamic Test ◽  
Full Scale ◽  
Flexible Pipe ◽  
Collapse Resistance ◽  
Potential Applications ◽  
Industrial Procurement ◽  
Tension Capacity

Ultra Deep Water (UDW) developments are now a reality with several fields below 2 000 m water depth now ready for production. Within the domain of flexible pipe technology for UDW, Technip identified a number of technical challenges such as flow assurance, riser tension capacity and hydrostatic collapse resistance. These challenges have been addressed through the qualification of various flexible pipe products/components and riser configurations. This paper will focus on one of the solutions developed which addresses the hydrostatic collapse resistance of the pipe, namely the dynamic PSI wire. The dynamic PSI wire was developed primarily as structurally optimized pressure armour. Based on the efficient structural cross section of the I-beam, the dynamic PSI wire provides a weight/strength optimized configuration for internal pressure capacity of the pipe. It also provides increased crushing strength for installation of the pipe in Ultra Deep Water and significantly increases the hydrostatic collapse resistance of the pipe. The objective of the development of the dynamic PSI wire was to propose a 12″ riser for 2 500 m water depth and smaller diameter down to 3 000 m. This objective has been reached, without impacting the dynamic and sour service capacity of the riser. The dynamic PSI wire has succeeded all the qualification process (industrial procurement & manufacturing, full scale dynamic test, full scale collapse tests, full scale offshore installation test down to 3 000m water depth, NACE test, etc) and is now deemed fully qualified for project application. This paper will present the qualification program and also some field case studies showing the potential applications of flexible risers integrating this new design. The availability of dynamic PSI wires provides operators with the opportunity to develop flexible riser production systems in UDW fields with larger diameters and therefore enhance the subsea production and export systems.

scholarly journals Experimental and Numerical Evaluation of Progressive Collapse Behavior in Scaled RC Beam-Column Subassemblage

2016 ◽  
Vol 2016 ◽  
pp. 1-17 ◽  
Author(s):  
Rasool Ahmadi ◽  
Omid Rashidian ◽  
Reza Abbasnia ◽  
Foad Mohajeri Nav ◽  
Nima Usefi
Keyword(s):  
Numerical Model ◽  
Progressive Collapse ◽  
Experimental Tests ◽  
Resistance Mechanisms ◽  
Full Scale ◽  
Displacement Curve ◽  
Rc Beam ◽  
Rc Structures ◽  
Collapse Behavior ◽  
Column Removal Scenario

An experimental test was carried out on a 3/10 scale subassemblage in order to investigate the progressive collapse behavior of reinforced concrete (RC) structures. Investigation of alternative load paths and resistance mechanisms in scaled subassemblage and differences between the results of full-scale and scaled specimens are the main goals of this research. Main characteristics of specimen response including load-displacement curve, mechanism of formation and development of cracks, and failure mode of the scaled specimen had good agreement with the full-scale specimen. In order to provide a reliable numerical model for progressive collapse analysis of RC beam-column subassemblages, a macromodel was also developed. First, numerical model was validated with experimental tests in the literature. Then, experimental results in this study were compared with validated numerical results. It is shown that the proposed macromodel can provide a precise estimation of collapse behavior of RC subassemblages under the middle column removal scenario. In addition, for further evaluation, using the validated numerical model, parametric study of new subassemblages with different details, geometric and boundary conditions, was also done.

Experimental Characterization of a Circular Diaphragm Dielectric Elastomer Generator

2014 ◽  
Author(s):  
Michele Righi ◽  
Rocco Vertechy ◽  
Marco Fontana
Keyword(s):  
Mechanical Response ◽  
Dielectric Elastomer ◽  
Experimental Characterization ◽  
Test Rig ◽  
High Voltage Direct Current ◽  
Wave Energy Converters ◽  
Adequate Knowledge ◽  
Dynamic Performances ◽  
Circular Diaphragm

Inflated Circular Diaphragm Dielectric Elastomer Generators (CD-DEGs) are a special embodiment of polymeric transducer that can be used to convert pneumatic energy into high-voltage direct-current electricity. Potential application of CD-DEGs is as power take-off system for wave energy converters that are based on the oscillating water column principle. Optimal usage of CD-DEGs requires the adequate knowledge of their dynamic electro-mechanical response. This paper presents a test-rig for the experimental study of the dynamic response of CD-DEGs under different programmable electro-mechanical loading conditions. Experimental results acquired on the test-rig are also presented, which highlight the dynamic performances of CD-DEGs that are based on acrylic elastomer membranes and carbon conductive grease electrodes.

Pseudo-Dynamic Test of Full-Scale Rcs Frame: Part I - Design, Construction, Testing

2004 ◽  
Author(s):  
C. H. Chen ◽  
W. C. Lai ◽  
P. Cordova ◽  
G. G. Deierlein ◽  
K. C. Tsai
Keyword(s):  
Dynamic Test ◽  
Full Scale ◽  
Design Construction

Modelling of Thermoacoustic Combustion Instabilities Phenomena: Application to an Experimental Rig for Testing Full Scale Burners

2014 ◽  
Author(s):  
Davide Laera ◽  
Giovanni Campa ◽  
Sergio M. Camporeale ◽  
Edoardo Bertolotto ◽  
Sergio Rizzo ◽  
...  
Keyword(s):  
Acoustic Analysis ◽  
Fem Analysis ◽  
Full Scale ◽  
Operating Conditions ◽  
System Modelling ◽  
Combustion Instabilities ◽  
Test Rig ◽  
Pressure Oscillations ◽  
Secondary Air ◽  
Actual Geometry

This paper concerns the acoustic analysis of self–sustained thermoacoustic pressure oscillations that occur in a test rig equipped with full scale lean premixed burner. The experimental work is conducted by Ansaldo Energia and CCA (Centro Combustione Ambiente) at the Ansaldo Caldaie facility in Gioia del Colle (Italy), in cooperation with Politecnico di Bari. The test rig is characterized by a longitudinal development with two acoustic volumes, plenum and combustion chamber, coupled by the burner. The length of both chambers can be varied with continuity in order to obtain instability at different frequencies. A previously developed three dimensional finite element code has been applied to carry out the linear stability analysis of the system, modelling the thermoacoustic combustion instabilities through the Helmholtz equation under the hypothesis of low Mach approximation. The heat release fluctuations are modelled according to the κ-τ approach. The burner, characterized by two conduits for primary and secondary air, is simulated by means of both a FEM analysis and a Burner Transfer Matrix (BTM) method in order to examine the influence of details of its actual geometry. Different operating conditions, in which self–sustained pressure oscillations have been observed, are examined. Frequencies and growth rates of unstable modes are identified, with good agreement with experimental data in terms of frequencies and acoustics pressure wave profiles.

Numerical Towing Model for LNG Carrier Approach in Exposed Environment Calibrated With Full-Scale Measurements and Operability Criterion

2021 ◽  
Author(s):  
Erwan Auburtin ◽  
Quentin Delivré ◽  
Jason McConochie ◽  
Jim Brown ◽  
Yuriy Drobyshevski
Keyword(s):  
Numerical Model ◽  
Degrees Of Freedom ◽  
Line Tension ◽  
Full Scale ◽  
Model Parameters ◽  
Wave Loads ◽  
Simplified Approach ◽  
Large Matrix ◽  
Multi Body ◽  
The Impact

Abstract The Prelude Floating Liquefied Natural Gas (FLNG) platform is designed to offload liquefied natural and petroleum gas products to carrier vessels moored in a Side-by-Side (SBS) configuration. Prior to the mooring operation, the carrier vessel is escorted and held alongside the FLNG with the assistance of tugs connected to her bow and stern to ensure sufficient control over the vessel in this critical phase. In order to better understand the impact of environmental conditions, to determine the optimum length, strength, material and configuration of the towline stretcher, and to estimate the maximum operable environments, coupled multi-body simulations have been performed in time domain. The numerical model, which considered both the LNG carrier and the forward tug, was calibrated using full-scale measurements of tug motions and tow line tension recorded during a real approach and berthing manoeuvre at Prelude FLNG. The measured environment effects were generated numerically and the model parameters were adjusted to reproduce the recorded behavior as accurately as possible. Since actions of the tug master are difficult to model numerically and only the statistical environment parameters are known, a simplified approach has been adopted for modelling the tug propulsion and steering using a combination of static forces, stiffness and linear and quadratic damping for relevant horizontal degrees of freedom. The calibrated numerical model was first subjected to several sensitivity assessments of the modelling level (single- or multi-body, inclusion of second-order wave loads, inclusion of forward speed). Then sensitivity studies were performed to help address operational requirements related to the wave height and direction, and the stretcher length and strength. The conclusions have been taken into consideration for the selection of the tow line configurations for future operations. Finally, the calibrated coupled LNG carrier and tug model was used to derive Prelude-specific tug operability criteria that may be used for decision-making based on weather forecasts, prior to the SBS offloading operations. A large matrix of swell and wind driven waves was simulated over a range of wave heights, periods, directions and static towing forces to allow a criterion to be developed based on a stochastic extreme tow line tension. Such criterion considers relevant wave parameters while remaining simplified enough for easy use in operations. This paper describes the assumptions and process to numerically model the towing configuration and calibrate the different coefficients, discusses the results obtained for the various sensitivities, and explains the operability criteria. Important conclusions and lessons learnt are also shared.

Numerical analysis of the transient wear and lubrication behaviors of misaligned journal bearings caused by linear shaft misalignment

2021 ◽  
pp. 1-17
Author(s):  
Tianyou Yang ◽  
Yanfeng Han ◽  
Yijia Wang ◽  
Guo Xiang
Keyword(s):  
Numerical Model ◽  
Film Thickness ◽  
Contact Pressure ◽  
Elastic Deformation ◽  
Journal Bearing ◽  
Fluid Pressure ◽  
Axial Direction ◽  
Wear Depth ◽  
Wear Process ◽  
Journal Misalignment

Abstract The purpose of this study is to investigate the role of the misalignment journal, caused by journal elastic deformation, on the transient wear and mixed lubrication performances using a numerical model. In the numerical model, the transient geometry lubrication clearance considering the journal misalignment, the transient elastic deformation and the transient wear depth are incorporated to evaluate the transient film thickness during wear process. The evolutions, under different external loads, of the wear depth, wear rate, elastic deformation, film thickness, fluid pressure and contact pressure are calculated by the numerical model. Furthermore, the calculated results of the misaligned journal bearing are compared with those of the aligned journal bearing. The results show that the distributions of the wear depth, film pressure and elastic deformation are asymmetric along the axial direction and the peak values of them shift toward the back end when the journal misalignment is considered. The maximum wear depth, maximum fluid pressure, maximum contact pressure and maximum elastic deformation of the misaligned journal condition are significantly larger than those of the aligned journal condition.

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