A vortex induced vibration of marine riser in waves

2011 ◽  
Vol 30 (4) ◽  
pp. 96-101 ◽  
Author(s):  
Min Lou ◽  
Wenyi Dong ◽  
Haiyan Guo
Keyword(s):  
Marine Riser ◽  
Vortex Induced Vibration

scholarly journals VIV Fracture Investigation into 3D Marine Riser with a Circumferential Outside Surface Crack

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Jun Liu ◽  
Zhigang Du ◽  
Xiaoqiang Guo ◽  
Liming Dai ◽  
Liang Huang ◽  
...  
Keyword(s):  
Vibration Amplitude ◽  
Lateral Displacement ◽  
Axial Stress ◽  
Assessment Model ◽  
Surface Cracks ◽  
Bending Stress ◽  
Marine Riser ◽  
Vortex Induced Vibration ◽  
Marine Risers ◽  
Failure Assessment

Vortex-induced vibration (VIV) is one of the most common dynamic mechanisms that cause damage to marine risers. Hamilton’s variational principle is used to establish a vortex-induced vibration (VIV) model of a flexible riser in which the wake oscillator model is used to simulate cross-flow (CF) and inline flow (IL) vortex-induced forces and their coupling, taking into account the effect of the top tension and internal flow in the riser. The VIV model is solved by combining the Newmark-β and Runge–Kutta methods and verified with experimental data from the literature. Combining Option 1 and Option 2 failure assessment diagrams (FADs) in the BS7910 standard, a fracture failure assessment model for a marine riser with circumferential semielliptical outside surface cracks is established. Using the VIV model and FAD failure assessment chart, the effects of riser length, inside/outside flows, and top tension on the VIV response and safety assessment of marine risers with outside surface cracks are investigated. It is shown that increasing the top tension can inhibit the lateral displacement amplitude and bending stress in a riser, but excessive top tension can increase the axial stress in the riser, which counteracts the decrease in the bending stress, so that the effect of top tension on crack safety is not significant. The increasing outside flow velocity significantly increases the lateral vibration amplitude and bending stress in the riser and reduces the crack safety. When other parameters remain unchanged, increasing riser length has no significant effect on the vibration amplitude of the lower part of the riser.

scholarly journals Vortex-Induced Vibration of a Marine Riser: Numerical Simulation and Mechanism Understanding

2020 ◽  
Author(s):  
Xiangxi Han ◽  
Youhong Tang ◽  
Zhiqiang Feng ◽  
Zhanbin Meng ◽  
Ang Qiu ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Marine Riser ◽  
Vortex Induced Vibration

A surrogate model for estimating uncertainty in marine riser fatigue damage resulting from vortex-induced vibration

2022 ◽  
Vol 254 ◽  
pp. 113796
Author(s):  
HyeongUk Lim ◽  
Lance Manuel ◽  
Ying Min Low ◽  
Narakorn Srinil
Keyword(s):  
Fatigue Damage ◽  
Surrogate Model ◽  
Marine Riser ◽  
Vortex Induced Vibration

Fatigue Reliability Evaluation of Marine Risers Under Vortex Induced Vibration

2013 ◽  
Author(s):  
Rizwan A. Khan ◽  
Suhail Ahmad
Keyword(s):  
Fatigue Crack ◽  
Crack Growth ◽  
Deep Sea ◽  
New Ventures ◽  
Limit State ◽  
Fatigue Reliability ◽  
Marine Riser ◽  
Vortex Induced Vibration ◽  
Finite Element Software ◽  
Bending Mode

Depleting oil reserves in shallow waters, off-shore oil fields are opening the avenues of new ventures in deep sea conditions. A marine riser is a major component of an offshore drilling and production system that are either fixed or floating in nature. Deepwater risers are quite long and significant currents usually excite natural bending mode that is much higher than the fundamental bending mode. In ultra deep environment currents usually change in magnitude and direction with depth, thereby inducing possibility of exciting multiple modes of the riser vibration due to VIV. Vortex induced vibration analysis has been carried out of a long marine riser in a probable deep sea location. To improve the understanding under deepwater harsh environments, the behavior of the riser under these forces is thoroughly investigated. 3D Nonlinear dynamic analysis of riser is obtained in the time domain using finite element software package ABAQUS/Aqua. The response histories so obtained are employed for the study of fatigue reliability analyses of riser. Uncertainty modeling, especially of fatigue crack growth parameters, is undertaken using bi-linear crack growth relationship. Results pertaining to fatigue reliability and fatigue crack size evolution are presented using Monte Carlo Simulation. The bi-linear crack growth models are found to lead to higher fatigue life estimation. Sensitivity behavior pertinent to limit state adopted has been thoroughly investigated. These findings implicate inspection schemes for components of the marine structures to ensure minimization of the surprises due to wide scatter of the fatigue phenomenon in marine environment.

Sign in / Sign up

Export Citation Format

Share Document