Experimental and Numerical Study of Damaged Tubular Members Under Lateral Loads

2002 ◽  
Author(s):  
Claudio Ruggieri ◽  
Jose´ Alfredo Ferrari
Keyword(s):  
Oil And Gas ◽  
Numerical Solutions ◽  
Production Systems ◽  
Numerical Study ◽  
Structural Response ◽  
Local Deformation ◽  
Structural Behavior ◽  
Lateral Loads ◽  
Nuclear Facilities ◽  
Linear Behavior

Structural behavior of dent damaged tubular members by local indentation remains a key issue for the safety and failure assessment of critical structures, including marine and nuclear facilities, oil and gas pipelines. This failure mode most often arises from very large localized plastic deformations caused mainly by excessive or accidental loads such as, for example, during the collision of adjacent risers in deepwater floating production systems (FPS). The complex interaction between the local deformation in the dented region and global bending of the tubular member may severely reduce the plastic collapse load while, at the same time, strongly affecting its load-deflection behavior. This study presents an experimental and numerical investigation of the structural behavior of a dented tubular member under lateral load which is applicable to marine risers. Experimental load-deflection curves measured using a 4 1/2″ O.D. (114 mm) API N80 pipe (580 MPa yield stress) with varying length characterize the plastic response during local indentation and global bending. 3D finite element models are employed to generate numerical solutions describing the large deformation, non-linear behavior for the tested pipes. The experimental results agree well with the numerical results. The analyses provide further insight into the structural response of tubular members and risers which dent damage effects.

Structural Behavior of Dented Tubular Members Under Lateral Loads

2004 ◽  
Vol 126 (2) ◽  
pp. 191-197 ◽  
Author(s):  
Claudio Ruggieri ◽  
Jose´ Alfredo Ferrari,
Keyword(s):  
Oil And Gas ◽  
Numerical Solutions ◽  
Production Systems ◽  
Structural Response ◽  
Local Deformation ◽  
Structural Behavior ◽  
Lateral Loads ◽  
Linear Behavior ◽  
Failure Assessment ◽  
Varying Length

Structural behavior of tubular members with dent damaged caused by local indentation remains a key issue for the safety and failure assessment of critical structures, including marine facilities, oil and gas pipelines. This failure mode most often arises from very large localized plastic deformations caused mainly by excessive or accidental loads such as, for example, during the collision of adjacent risers in deepwater floating production systems (FPS). The complex interaction between the local deformation in the dented region and global bending of the tubular member may severely reduce the plastic collapse load which strongly affects its load-deflection behavior. This study presents an experimental and numerical investigation of the structural behavior of a dented tubular member under lateral load which is applicable to marine risers. Experimental load-deflection curves measured using a 412″O.D. (114 mm) API N80 pipe (580 MPa yield stress) with varying length characterize the plastic response during local indentation and global bending. 3D finite element models are employed to generate numerical solutions describing the large deformation, non-linear behavior for the tested pipes. The experimental results agree well with the numerical results. The analyses provide further insight into the structural response of tubular members and risers with dent damage effects.

scholarly journals Structural Response of a Single-Stage Centrifugal Compressor to Fluid-Induced Excitations at Low-Flow Operating Condition: Experimental and Numerical Study

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4292
Author(s):  
Kirill Kabalyk ◽  
Andrzej Jaeschke ◽  
Grzegorz Liśkiewicz ◽  
Michał Kulak ◽  
Tomasz Szydłowski ◽  
...  
Keyword(s):  
Centrifugal Compressor ◽  
Numerical Study ◽  
Structural Response ◽  
Flow Coefficient ◽  
Low Flow ◽  
Dynamic Strain ◽  
Duct Acoustics ◽  
Numerical Noise ◽  
Partial Load ◽  
Compressor Impeller

The article describes an assessment of possible changes in constant fatigue life of a medium flow-coefficient centrifugal compressor impeller subject to operation at close-to-surge point. Some aspects of duct acoustics are additionally analyzed. The experimental measurements at partial load are presented and are primarily used for validation of unidirectionally coupled fluid-structural numerical model. The model is based on unsteady finite-volume fluid-flow simulations and on finite-element transient structural analysis. The validation is followed by the model implementation to replicate the industry-scale loads with reasonably higher rotational speed and suction pressure. The approach demonstrates satisfactory accuracy in prediction of stage performance and unsteady flow field in vaneless diffuser. The latter is deduced from signal analysis relying on continuous wavelet transformations. On the other hand, it is found that the aerodynamic incidence losses at close-to-surge point are underpredicted. The structural simulation generates considerable amounts of numerical noise, which has to be separated prior to evaluation of fluid-induced dynamic strain. The main source of disturbance is defined as a stationary region of static pressure drop caused by flow contraction at volute tongue and leading to first engine-order excitation in rotating frame of reference. Eventually, it is concluded that the amplitude of excitation is too low to lead to any additional fatigue.

A numerical study of the interaction between unsteay free-stream disturbances and localized variations in surface geometry

1989 ◽  
Vol 209 ◽  
pp. 285-308 ◽  
Author(s):  
R. J. Bodonyi ◽  
W. J. C. Welch ◽  
P. W. Duck ◽  
M. Tadjfar
Keyword(s):  
Numerical Solutions ◽  
Free Stream ◽  
Stokes Equations ◽  
Numerical Study ◽  
Navier Stokes ◽  
Surface Geometry ◽  
Navier Stokes Equations ◽  
S Waves ◽  
Tollmien Schlichting

A numerical study of the generation of Tollmien-Schlichting (T–S) waves due to the interaction between a small free-stream disturbance and a small localized variation of the surface geometry has been carried out using both finite–difference and spectral methods. The nonlinear steady flow is of the viscous–inviscid interactive type while the unsteady disturbed flow is assumed to be governed by the Navier–Stokes equations linearized about this flow. Numerical solutions illustrate the growth or decay of the T–S waves generated by the interaction between the free-stream disturbance and the surface distortion, depending on the value of the scaled Strouhal number. An important result of this receptivity problem is the numerical determination of the amplitude of the T–S waves.

A Numerical and Experimental Investigation of Turbulent Heat Transport Downstream From an Abrupt Pipe Expansion

1983 ◽  
Vol 105 (4) ◽  
pp. 862-869 ◽  
Author(s):  
R. S. Amano ◽  
M. K. Jensen ◽  
P. Goel
Keyword(s):  
Heat Transfer ◽  
Numerical Solutions ◽  
Numerical Study ◽  
Separated Flow ◽  
Flow Region ◽  
Reynolds Numbers ◽  
Turbulent Heat ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Pipe Expansion

An experimental and numerical study is reported on heat transfer in the separated flow region created by an abrupt circular pipe expansion. Heat transfer coefficients were measured along the pipe wall downstream from an expansion for three different expansion ratios of d/D = 0.195, 0.391, and 0.586 for Reynolds numbers ranging from 104 to 1.5 × 105. The results are compared with the numerical solutions obtained with the k ∼ ε turbulence model. In this computation a new finite difference scheme is developed which shows several advantages over the ordinary hybrid scheme. The study also covers the derivation of a new wall function model. Generally good agreement between the measured and the computed results is shown.

Stability of offshore structures in shallow water depth

2011 ◽  
Vol 2 (2) ◽  
pp. 320-333
Author(s):  
F. Van den Abeele ◽  
J. Vande Voorde
Keyword(s):  
Shallow Water ◽  
Water Depth ◽  
Fossil Fuels ◽  
Oil And Gas ◽  
Structural Response ◽  
Offshore Structures ◽  
Exploration And Production ◽  
Subsea Pipelines ◽  
Wave Induced ◽  
Shallow Water Depth

The worldwide demand for energy, and in particular fossil fuels, keeps pushing the boundaries of offshoreengineering. Oil and gas majors are conducting their exploration and production activities in remotelocations and water depths exceeding 3000 meters. Such challenging conditions call for enhancedengineering techniques to cope with the risks of collapse, fatigue and pressure containment.On the other hand, offshore structures in shallow water depth (up to 100 meter) require a different anddedicated approach. Such structures are less prone to unstable collapse, but are often subjected to higherflow velocities, induced by both tides and waves. In this paper, numerical tools and utilities to study thestability of offshore structures in shallow water depth are reviewed, and three case studies are provided.First, the Coupled Eulerian Lagrangian (CEL) approach is demonstrated to combine the effects of fluid flowon the structural response of offshore structures. This approach is used to predict fluid flow aroundsubmersible platforms and jack-up rigs.Then, a Computational Fluid Dynamics (CFD) analysis is performed to calculate the turbulent Von Karmanstreet in the wake of subsea structures. At higher Reynolds numbers, this turbulent flow can give rise tovortex shedding and hence cyclic loading. Fluid structure interaction is applied to investigate the dynamicsof submarine risers, and evaluate the susceptibility of vortex induced vibrations.As a third case study, a hydrodynamic analysis is conducted to assess the combined effects of steadycurrent and oscillatory wave-induced flow on submerged structures. At the end of this paper, such ananalysis is performed to calculate drag, lift and inertia forces on partially buried subsea pipelines.

3-D Numerical Simulations of Subsea Jumper Transporting Intermittent Slug Flows

2018 ◽  
Author(s):  
Jihyeon Kim ◽  
Narakorn Srinil
Keyword(s):  
Slug Flow ◽  
Oil And Gas ◽  
Process Condition ◽  
Structural Response ◽  
Dynamic Responses ◽  
Operating Pressure ◽  
Computational Performance ◽  
Fluid Properties ◽  
Slug Flows ◽  
Interaction Approach

Subsea jumper is the steel pipe structure to connect wellhead and subsea facilities such as manifolds or processing units in order to transport the produced multiphase flows. Generally, the jumper consists of a goalpost with two loop structures and a straight pipe between them, carrying the multiphase oil and gas from the producing well. Due to the jumper pipe characteristic geometry and multi-fluid properties, slug flows may take place, creating problematic fluctuating forces causing the jumper oscillations. Severe dynamic fluctuations cause the risk of pipe deformations and resonances resulting from the hydrodynamic momentum/pressure forces which can lead to unstable operating pressure and decreased production rate. Despite the necessity to design subsea jumper with precise prediction on the process condition and the awareness of slug flow risks, it is challenging to experimentally evaluate, identify and improve the modified design in terms of the facility scale, time and cost efficiency. With increasing high computational performance, numerical analysis provides an alternative approach to simulate multiphase flow-induced force effects on the jumper. The present paper discusses the modelling of 3-D flow simulations in a subsea jumper for understanding the development process of internal slug flows causing hydrodynamic forces acting on the pipe walls and bends. Based on the fluctuating pressure calculated by the fluid solver, dynamic responses of the jumper pipe are assessed by a one-way interaction approach to evaluate deformation and stress. A potential resonance is discussed with the jumper modal analysis. Results from the structural response analyses show dominant multi-modal frequencies due to intermittent slug flow frequencies. Numerical results and observed behaviors may be useful for a comparison with other simulation and experiment.

Computational Fluid Dynamics Evaluation of Heat Transfer Correlations for Sodium Flows in a Heat Exchanger

2010 ◽  
Vol 132 (5) ◽  
Author(s):  
Seok-Ki Choi ◽  
Seong-O Kim ◽  
Hoon-Ki Choi
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Turbulence Model ◽  
Numerical Solutions ◽  
Numerical Study ◽  
Cross Flow ◽  
Turbulence Models ◽  
Parallel Flow ◽  
Sst Model ◽  
Heat Transfer Correlations

A numerical study for the evaluation of heat transfer correlations for sodium flows in a heat exchanger of a fast breeder nuclear reactor is performed. Three different types of flows such as parallel flow, cross flow, and two inclined flows are considered. Calculations are performed for these three typical flows in a heat exchanger changing turbulence models. The tested turbulence models are the shear stress transport (SST) model and the SSG-Reynolds stress turbulence model by Speziale, Sarkar, and Gaski (1991, “Modelling the Pressure-Strain Correlation of Turbulence: An Invariant Dynamical System Approach,” J. Fluid Mech., 227, pp. 245–272). The computational model for parallel flow is a flow past tubes inside a circular cylinder and those for the cross flow and inclined flows are flows past the perpendicular and inclined tube banks enclosed by a rectangular duct. The computational results show that the SST model produces the most reliable results that can distinguish the best heat transfer correlation from other correlations for the three different flows. It was also shown that the SSG-RSTM high-Reynolds number turbulence model does not deal with the low-Prandtl number effect properly when the Peclet number is small. According to the present calculations for a parallel flow, all the old correlations do not match with the present numerical solutions and a new correlation is proposed. The correlations by Dwyer (1966, “Recent Developments in Liquid-Metal Heat Transfer,” At. Energy Rev., 4, pp. 3–92) for a cross flow and its modified correlation that takes into account of flow inclination for inclined flows work best and are accurate enough to be used for the design of the heat exchanger.

In-plane response of unreinforced masonry walls confined by reinforced concrete tie-columns and tie-beams

2017 ◽  
Vol 20 (11) ◽  
pp. 1632-1643 ◽  
Author(s):  
Masoud Amouzadeh Tabrizi ◽  
Masoud Soltani
Keyword(s):  
Numerical Study ◽  
Nonlinear Behavior ◽  
Numerical Approach ◽  
Masonry Wall ◽  
Masonry Walls ◽  
Lateral Loads ◽  
Confined Masonry ◽  
Smeared Crack ◽  
Modeling Strategy ◽  
Reversed Cyclic

This article focuses on the experimental and analytical investigations of masonry walls surrounded by tie-elements under in-plane loads. The experimental results of an unconfined and a confined masonry wall, tested under reversed cyclic lateral loads, are presented. For numerical study, a micro-modeling strategy, using smeared-crack-based approach, is adopted. In order to validate the numerical approach, experimental test results and data obtained from the literature are used, and through a systematic parametric study, the influence of adjoining walls and number of tie-columns on the seismic behavior of confined masonry panels is numerically assessed and a simple but rational method for predicting the nonlinear behavior of these structures is proposed.

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