Experimental and Numerical Study on Dynamic Response of FSRU-LNGC Side-by-Side Mooring System

2019 ◽  
Author(s):  
Jingxia Yue ◽  
Weili Kang ◽  
Wengang Mao ◽  
Pengfei Chen ◽  
Xi Wang
Keyword(s):  
Numerical Analysis ◽  
Dynamic Response ◽  
Numerical Study ◽  
Clean Energy ◽  
Coupled Analysis ◽  
Response Analysis ◽  
Mooring System ◽  
Test Results ◽  
Floating Bodies ◽  
Damping Parameter

Abstract Floating Storage and Regasification Unit (FSRU) becomes one of the most popular equipment in the industry for providing clean energy due to its technical, economic and environmental features. Under the combined loads from wind, wave and current, it is difficult for the prediction of the dynamic response for such FSRU-LNGC (Liquified Natural Gas Carrier) side-by-side mooring system, because of the complicated hydrodynamic interaction between the two floating bodies. In this paper, a non-dimensional damping parameter of the two floating bodies is obtained from a scaled model test. Then the numerical analysis is carried out based on the test results, and the damping lid method is applied to simulate the hydrodynamic interference between floating bodies. The dynamic response of the side-by-side mooring system including six degrees of freedom motion, cable tension and fender force are provided and analyzed. According to the comparisons between numerical results and the test results, it is shown that the proposed coupled analysis model is reliable, and the numerical analysis can properly describe the dynamic response of the multi-floating mooring system in the marine environment. Moreover, the non-dimensional damping parameter which is used in numerical analysis can act as a good reference to the dynamic response analysis of similar multi-floating mooring systems.

Dynamic response analysis of a floating mooring system

2014 ◽  
Vol 13 (3) ◽  
pp. 381-389 ◽  
Author(s):  
Conghuan Le ◽  
Hongyan Ding ◽  
Puyang Zhang
Keyword(s):  
Dynamic Response ◽  
Response Analysis ◽  
Mooring System ◽  
Dynamic Response Analysis

scholarly journals Performance validation and dynamic response analysis of a deepwater cable bending restrictor

2020 ◽  
Vol 37 (3) ◽  
pp. 95-101
Author(s):  
Kang Yongtian ◽  
Xiao Wensheng ◽  
Zhang Dagang ◽  
Zhang Liang ◽  
Zhou Chouyao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Numerical Analysis ◽  
Dynamic Response ◽  
Bending Stiffness ◽  
Offshore Wind ◽  
Response Analysis ◽  
Analysis Model ◽  
Element Analysis ◽  
Cable Structure ◽  
Pipe Model

The deepwater cable bending restrictor is an important protective device for risers, umbilicals and cables in offshore engineering, protecting cable structure by controlling minimum bending radius. Its mechanical properties are analysed based on the numerical analysis model and finite element analysis (FEM) of ø175. The sensitivity analysis of using quantity of bending restrictors is also performed to show the effect of the quantity on bending stiffness. A testing scheme of bending stiffness of the bending restrictor is then formulated based on its structure. From numerical analysis results through test simulation, the tolerance is less than 3 %, which verifies the reliability of the numerical analysis model. Performance of the bending restrictor and dynamic response are analysed according to environmental parameters that occur once per 100 years from offshore wind power farms and pipein-pipe models, respectively. The results show the bending restrictor can effectively protect cable structure, and the pipein-pipe model is suitable for calculating mechanical properties of interaction between the bending restrictor and cable.

Modeling and Dynamic Response Analysis of an Point Supported Plate by Using ANSYS and MATLAB

2012 ◽  
Vol 445 ◽  
pp. 1088-1093
Author(s):  
Cihan Demir ◽  
Yunus Alapan
Keyword(s):  
Mathematical Model ◽  
Dynamic Response ◽  
Mixed Boundary ◽  
Mixed Boundary Conditions ◽  
Response Analysis ◽  
Fe Model ◽  
Test Results ◽  
Dynamic Response Analysis ◽  
Processing Times ◽  
Principal Coordinates

The dynamic behavior of plates with mixed boundary conditions has been the subject of intensive study for many years due to its great importance in many engineering applications. On-trend approach in dynamic response analysis is to combine mathematical model, test results and computer simulation. Classical techniques of mathematical modeling of intricate structural systems for response analysis in frequency or time domain are tiresome and time consuming. In this study, a point supported rectangular plate considered and extraction of its system model from FE model, validated by the test results, by using commercially available computer programs such as Ansys and Matlab is demonstrated. State space mathematical model in principal coordinates obtained in Matlab from the modal analysis results of its FE model. Its modes sorted with respect to peak gain values, and the modes with the less contributions to the response truncated. To validate the accuracy of this method and truncation, transient responses from the full model with no reduction, truncated model, and Ansys are compared and found to be in accord with each other. Its demonstrated by plotting the indicated results of analyses, and emphasized the significant processing times between the conventional approach and stated method. It is concluded obvious that this study will make a good understanding in simplifying the dynamic analysis of vibration problems of plates.

Experimental and Numerical Study on Large Truncation of Deepwater Mooring Line

2009 ◽  
Author(s):  
Yihua Su ◽  
Jianmin Yang ◽  
Longfei Xiao ◽  
Gang Chen
Keyword(s):  
Dynamic Response ◽  
Water Depth ◽  
Numerical Study ◽  
Unit Length ◽  
Low Frequency ◽  
Model Tests ◽  
Mooring Line ◽  
Mooring System ◽  
Mooring Lines ◽  
Wave Basin

Modeling the deepwater mooring system in present available basin using standard Froude scaling at an acceptable scale presents new challenges. A prospective method is to truncate the full-depth mooring lines and find an equivalent truncated mooring system that can reproduce both static and dynamic response of the full-depth mooring system, but large truncation arise if the water depth where the deepwater platform located is very deep or the available water depth of the basin is shallow. A Cell-Truss Spar operated in 1500m water depth is calibrated in a wave basin with 4m water depth. Large truncation arises even though a small model scale 1:100 is chosen. A series of truncated mooring lines are designed and investigated through numerical simulations, single line model tests and coupled wave basin model tests. It is found that dynamic response of the truncated mooring line can be enlarged by using larger diameter and mass per unit length in air. Although the truncated mooring line with clump presents a “taut” shape, its dynamic characteristics is dominated by the geometry stiffness and it underestimates dynamic response of the full-depth mooring line, even induces high-frequency dynamic response. There are still two obstacles in realizing dynamic similarity for the largely truncated mooring system: lower mean value of the top tension of upstream mooring lines, and smaller low-frequency mooring-induced damping.

Numerical study of dynamic response analysis of slag behaviors in an entrained flow gasifier

Fuel ◽  
2018 ◽  
Vol 234 ◽  
pp. 1071-1080 ◽  
Author(s):  
Binbin Zhang ◽  
Zhongjie Shen ◽  
Qinfeng Liang ◽  
Jianliang Xu ◽  
Haifeng Liu
Keyword(s):  
Dynamic Response ◽  
Numerical Study ◽  
Response Analysis ◽  
Dynamic Response Analysis ◽  
Entrained Flow ◽  
Entrained Flow Gasifier

An innovative mooring system for floating storage tanks and stochastic dynamic response analysis

2018 ◽  
Vol 170 ◽  
pp. 361-373 ◽  
Author(s):  
Ling Wan ◽  
Chi Zhang ◽  
Allan Ross Magee ◽  
Jingzhe Jin ◽  
Mengmeng Han ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Response Analysis ◽  
Stochastic Dynamic ◽  
Mooring System ◽  
Storage Tanks ◽  
Dynamic Response Analysis

Experimental and Numerical Study on the Hydrodynamic Properties of a Simplified Floating Hydrocarbon Storage Facility

2019 ◽  
Author(s):  
Chi Zhang ◽  
Nuno Fonseca ◽  
Allan R. Magee ◽  
Nianxin Ren
Keyword(s):  
Free Surface ◽  
Numerical Analysis ◽  
Numerical Study ◽  
Experimental Studies ◽  
Linear Potential ◽  
Mooring System ◽  
Storage Facility ◽  
Hydrodynamic Properties ◽  
Analysis Tools ◽  
Hydrocarbon Storage

Abstract A compliant modular floating hydrocarbon storage facility (FHSF) has been proposed for ocean space utilization. The FHSF consists of many floating hydrocarbon storage tanks (FHST) and several surrounding barges. These modules are connected in proximity through soft mooring system which reduces the environmental loads significantly. However, there are concerns on the potential resonance in the narrow gaps and the strong hydrodynamic interactions. This paper focuses on the hydrodynamic properties of a simplified subsystem which qualitatively represents part of the behavior of the entire FHSF but with reduced complexity. This subsystem consists of two FHSTs and a barge frame and is suitable for evaluating numerical analysis tools. Experimental studies on the subsystem and the complete system were performed in the ocean basin in SINTEF Ocean. A series of random, wide-band and realistic random wave tests were carried out to generate benchmark data to verify numerical analysis tools. Empty, partially loaded and fully loaded conditions were tested. The free surface elevations in the narrow gap and in the internal tank were obtained. A frequency domain numerical model of the subsystem was established in WAMIT based on linear potential theory. Higher order boundary element method (HOBEM) has been utilized to improve the accuracy and convergence. The influence of internal liquid (sloshing) inside the tanks is also considered in the linear range. The mooring system is simplified as linear springs. Linearized damping is introduced. The response amplitude operators (RAOs) of 6 degrees of freedom (D.O.F) and free surface elevations from numerical and experimental studies under the head sea conditions are compared. Good agreement on the motion RAOs are found, but significant differences are found on the RAOs of the elevation of the free surface. Finally, the influence of significant gap resonances is used to generate insight into how these problems might be mitigated.

PSEUDO-DYNAMIC RESPONSE TESTS ON SELF-RETURNING JOINT MECHANISM USING Ni-Ti-Co ALLOY

2006 ◽  
Vol 20 (25n27) ◽  
pp. 4439-4444
Author(s):  
JAE-HYOUK CHOI ◽  
KENICHI OHI
Keyword(s):  
Dynamic Response ◽  
Original Position ◽  
Response Analysis ◽  
Elastic Model ◽  
Test Results ◽  
Frame System ◽  
Joint Mechanism ◽  
Endplate Connection ◽  
Nonlinear Elastic ◽  
Steel Bolts

This paper deals with a beam-to-column connection using mechanical fasteners made of shape memory alloy, abbreviated as 'SMA bolt' hereafter. A flush-type endplate connection at beam-ends is arranged by use of SMA bolts, and the connection works as a super-elastic joint mechanism. This paper describes sub-structure pseudo-dynamic response tests on a super-elastic frame system with fictitious tension-bar diagonal braces. For the comparison, a similar structural system bolted by ordinary mild-steel bolts is also tested pseudo-dynamically. It was observed that the SMA bolt system returned to its original position, while the ordinary bolt system showed some permanent set after earthquakes. Additionally, response analysis based on a nonlinear-elastic model and a slip model is performed and compared with the test results.

scholarly journals Stochastic Dynamic Response Analysis of a 10 MW Tension Leg Platform Floating Horizontal Axis Wind Turbine

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3341 ◽  
Author(s):  
Tao Luo ◽  
De Tian ◽  
Ruoyu Wang ◽  
Caicai Liao
Keyword(s):  
Dynamic Response ◽  
Horizontal Axis ◽  
Viscous Drag ◽  
Response Analysis ◽  
Stochastic Dynamic ◽  
Mooring System ◽  
Wave Load ◽  
Tension Leg Platform ◽  
Horizontal Axis Wind Turbine ◽  
Resonant Amplitude

The dynamic response of floating horizontal axis wind turbines (FHWATs) are affected by the viscous and inertia effects. In free decay motion, viscous drag reduces the amplitude of pitch and roll fluctuation, the quasi-static mooring system overestimates the resonant amplitude values of pitch and roll. In this paper, the quasi-static mooring system is modified by introducing linear damping and quadratic damping. The dynamic response characteristics of the FHAWT modified model of the DTU 10 MW tension leg platform (TLP) were studied. Dynamic response of the blade was mainly caused by wind load, while the wave increased the blade short-term damage equivalent load. The tower base bending moment was affected by inclination of the tower and the misaligned angle βwave between wind and wave. Except the yaw motion, other degrees of freedom motions of the TLP were substantially affected by βwave. Ultimate tension of the mooring system was related to the displacement caused by pitch and roll motions, and standard deviation of the tension was significantly affected by the wave frequency response. Under the action of wave load, the viscous drag would stimulate the mooring system and increase the resonance of the platform motion.

Sign in / Sign up

Export Citation Format

Share Document