Dynamic Response Analysis on Flexible Riser With Different Configurations in Deep-Water Based on FEM Simulation

2018 ◽  
Author(s):  
Shuangxi Guo ◽  
Yilun Li ◽  
Min Li ◽  
Weimin Chen ◽  
Yue Kong
Keyword(s):  
Dynamic Response ◽  
Numerical Simulations ◽  
Deep Water ◽  
Dynamic Responses ◽  
Body Motion ◽  
Response Analysis ◽  
Flexible Beam ◽  
Nonlinear Dynamic Model ◽  
Nonlinear Fem ◽  
Structural Length

For case of oil/gas exploitation and mining in deep water, the length of riser is pretty large and, consequently, it brings huge challenges in both offshore installation and production operations and results in significant cost elevation due to the factors such as extreme tension loads induced from riser suspended self-weight and large structural flexibility. Therefore, there are several alternative riser configurations, e.g. lazy wave, hybrid tower and lazy-wave riser beside free hanging catenary, which have been proposed. In this paper, the dynamic characteristics and responses of several risers with typical configurations are considered and compared with each other based on our numerical simulations. Firstly, the nonlinear dynamic model of the riser systems are developed based on our 3d dynamic riser equations along with the modified FEM simulations. Then the dynamic response is analyzed based on our 3d curved flexible beam approach where the structural curvature changes with its spatial position and time in terms of vector equations. Compared with the linear approach, the nonlinear FEM method is used so as to consider large displacement/deformation, configuration geometry and structural stiffness changing with body motion. Moreover, the hydrodynamic force is considered as being related to body motion too. Based on the FEM numerical simulations, the influences of the amplitude/frequency of the top vessel motion along with the buoyancy modules/tower distribution along structural length on riser’s dynamic responses, in terms of the temporal-spatial evolution of displacement, curvature/bending stress and dynamic tension, are studied for different riser’s configurations. Our results show that the dynamic responses, particularly the maximum top tension, of different riser systems significantly change. Among the examined riser configurations, the response of the riser with more buoyancy modules may have lower value, and buoyancy distribution along structural length can influence the top tension and curvature.

Dynamic Response Analysis of Jacket Wharf Structure under Wave

2012 ◽  
Vol 226-228 ◽  
pp. 1353-1358
Author(s):  
Yuan Zhang ◽  
Ting Guo Chen
Keyword(s):  
Reinforced Concrete ◽  
Dynamic Response ◽  
Deep Water ◽  
Pile Foundation ◽  
Dynamic Responses ◽  
Response Analysis ◽  
Wave Load ◽  
Pull Out ◽  
Concrete Pile ◽  
Steel Piles

With the large ship transportation for bulk cargo marine development, construction of modern offshore deep water wharf is becoming more and more important. Based on the view of domestic offshore deep water wharf, the jacket structure was proposed as deep water light wharf. In consideration of the structure dynamic responses and the pile foundation pull-out resistance, three types of pile foundation were adopted, which are the hollow steel piles, the reinforced concrete pile and the hollow steel piles poured with granular materials. By finite element method the vibration characteristic and transient dynamic response to wave load were calculated. The results show that the jacket structure’s dynamic response to wave is not obvious. Also the structure with reinforced concrete pile can reduce the structure vibration displacement.

Dynamic Response Analysis of Bridge Pier Subject to Earthquake and Ice Loads

2011 ◽  
Vol 250-253 ◽  
pp. 2211-2215
Author(s):  
Fu Qiang Qi
Keyword(s):  
Dynamic Response ◽  
Dynamic Equilibrium ◽  
Work Conditions ◽  
Bridge Pier ◽  
Dynamic Responses ◽  
Response Analysis ◽  
Analysis Method ◽  
Equilibrium Equations ◽  
Different Types ◽  
Ice Loads

In order to discuss the effect of earthquake and dynamic ice loads to a bridge pier, this paper considered the effect of added mass of dynamic water, and it deduced the dynamic equilibrium equations for a bridge pier subject to earthquake and dynamic ice loads on the basis of nonlinear Morision equation. Using numerical analysis method, it discussed the dynamic response of a bridge pier subject to different types of earthquake loads, forced ice loads, and both earthquake and forced ice loads. Through comparing the pier responses in different work conditions, it discovered that the dynamic responses of the bridge pier subject to forced dynamic ice loads rise and fall severely at the time of ice buckling broken periodic change. The coupling effects of forced dynamic ice loads and earthquake especially near-fault earthquake enhance the dynamic response of bridge pier significantly.

Study on the Shaking Dynamic Response of Steam Generator LOCA

2018 ◽  
Author(s):  
Qian Huang ◽  
Xiaofei Yu ◽  
Huanhuan Qi ◽  
Naibin Jiang ◽  
Fengchun Cai ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Steam Generator ◽  
Power Plants ◽  
Tube Bundle ◽  
Response Analysis ◽  
Nonlinear Fem ◽  
Rarefaction Analysis ◽  
Dynamic Response Analysis ◽  
Reactor Coolant ◽  
Coolant Loop

Dynamic response research of steam generator loss of coolant accident (SG LOCA) is essential for the reliability and safety consideration. According to the differences of LOCA loading phenomena, two types of LOCA loads affect the SG: rarefaction wave travels through the primary fluid in the U-tubes, and the SG shakes due to reactor coolant loop(RCL) motions transmitted by the primary loop piping, former loading phenomena evaluation is called SG rarefaction analysis while latter is called shaking analysis. This paper place particular emphasis on shaking analysis. At present, the published literatures about LOCA mainly focus on RCL LOCA, reactor LOCA and fuel assembly LOCA, few reports concentrate on shaking dynamic response analysis of SG LOCA. Both Westinghouse and AREVA’s methods according to their research reports are to decouple the SG from the RCL: This method results in low computational efficiency as RCL LOCA and SG LOCA are evaluated separately and the decoupling error is uncertainty, meanwhile, in the vicinity of the nodes where the displacements are imposed, distorted reaction forces are usually found. Through reasonable simplification and equivalence, a detailed nonlinear FEM model of steam generator (SG) of a China 3rd generation nuclear power plant (NPP) is established, this model is then connected with the reactor coolant loop (RCL) to carry out the SG LOCA shaking dynamic response analysis. By calculation, the maximum absolute stresses of SG heat transfer tube bundle and its variation with tube diameter and upper supports reacting forces are obtained. In order to study the effect of SG decoupling from the RCL on shaking dynamic response, a comparative study of decoupling /coupling methods is conducted. Results shows that SG decoupling has a significant impact on the calculation result, the calculation method of coupling is more closer to the real situation and worthy to recommended. Related analytical procedures and calculation results lay the foundation for future SG shaking dynamic analysis and SG design of subsequent power plants.

Dynamic Response of Spar Wind Turbine Moored by Dynamic Catenaries Under Random Wind and Wave Loads

2019 ◽  
Author(s):  
Yilun Li ◽  
Shuangxi Guo ◽  
Yue Kong ◽  
Weimin Chen ◽  
Min Li
Keyword(s):  
Dynamic Response ◽  
Wind Turbine ◽  
Integrated System ◽  
Mooring Line ◽  
Offshore Wind Turbine ◽  
Response Analysis ◽  
Flexible Beam ◽  
Wave Loads ◽  
Wave Load ◽  
Floating Wind Turbine

Abstract As offshore wind turbine is developed toward larger water depth, the dynamics coming from structural and fluid inertia and damping effects of the mooring-line gets more obvious, that makes the response analysis of the large floating wind turbine under wind&wave load more challenging. In this study, the dynamic response of a spar floating wind turbine under random wind and wave loads is examined by the modified FEM simulations. Here an integrated system including flexible multi-bodies such as blades, tower, spar and mooring-lines is considered while the catenary dynamics is involved. The dynamic restoring performance of the catenary mooring-line is analyzed based on the vector equations of 3D curved flexible beam and its numerical simulations. Then the structural responses, e.g. the top tension, structural displacements and stress of the tower and the blade, undergoing random wind&wave loads, are examined. Morevoer, the influences of the catenary dynamics on its restoring performance and the hysteresis behavior are presented. Our numerical results show: the dynamics of mooring-line may significantly increase the top tension, and, particularly, the snap tension could be more than 3 times larger than the quasi-static one. Moreover, the structural response under random wind&wave load gets smaller mainly because of the hysteresis effect coming from the mooring-line dynamics. The floating body displacement at surge frequency is around 20% smaller, and the tower root stress at bending frequency is about 30% smaller than the quasi-static values respectively.

Nonlinear Dynamic Response Analysis of Aircraft Landing Gear with Finite Element Modeling

2016 ◽  
Vol 826 ◽  
pp. 23-27
Author(s):  
Wei Guo Wu ◽  
Zhen Tao Wang ◽  
Teng Jia
Keyword(s):  
Dynamic Response ◽  
Nonlinear Response ◽  
Shock Absorber ◽  
Landing Gear ◽  
Response Analysis ◽  
Nonlinear Fem ◽  
Fem Model ◽  
Nonlinear Dynamic Response ◽  
Aircraft Landing ◽  
Aircraft Landing Gear

The precise model and the analysis of nonlinear response are important for the landing gear research. In this paper, the FEM model of landing gear was established. The shock absorber is modeled with the nonlinear spring and damper. Random displacements were applied for simulating runway unevenness at aircraft taxiing. Through the simulation, the nonlinear FEM dynamic response of landing gear was acquired. The results show that: the stress of landing gear is large in the landing progress, especially for the random displacements; the weakness of landing gear is the axle sleeve. So the material and technology of the axle sleeve are important in the design of landing gear.

scholarly journals Numerical earthquake response analysis of the Liyutan earth dam in Taiwan

2010 ◽  
Vol 10 (6) ◽  
pp. 1269-1280 ◽  
Author(s):  
Z. Feng ◽  
P. H. Tsai ◽  
J. N. Li
Keyword(s):  
Dynamic Response ◽  
Function Analysis ◽  
Dynamic Responses ◽  
Earth Dam ◽  
Response Analysis ◽  
Vertical Acceleration ◽  
Seepage Analysis ◽  
Time Frequency ◽  
Acceleration Time Histories ◽  
Transfer Function Analysis

Abstract. The dynamic response of the Liyutan earth dam to the 1999 Chi-Chi earthquake (ML=7.3) in Taiwan was numerically analyzed. First, the staged construction of the dam was simulated. Then, seepage analysis, considering a 60-m water level, was performed. After seepage analysis, the initial static stress (prior to dynamic loading) was established in the dam. Both the horizontal and vertical acceleration time histories recorded at the base of the dam were used in the numerical simulations. The dynamic responses of the dam were analyzed for 50 s in the time domain. The simulated results were in agreement with the monitored data. The transfer function analysis and Hilbert-Huang Transform (HHT) were used to compare the results and to perceive the response characteristics of the dam. In particular, the time-frequency-energy plots of the HHT can reveal the timing and time frame of the dominant frequencies of the dynamic response. The influences of the initial shear modulus and uni-axial earthquake loading were also investigated.

Dynamic Response Analysis of Floating Storage Tank System Considering Hydrodynamic and Mechanical Interactions

2018 ◽  
Author(s):  
Ling Wan ◽  
Chi Zhang ◽  
Allan Ross Magee ◽  
Jingzhe Jin ◽  
Mengmeng Han ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Storage Tank ◽  
Hydrodynamic Interaction ◽  
Dynamic Responses ◽  
Hydrodynamic Interactions ◽  
Pile Foundations ◽  
Response Analysis ◽  
Mechanical Interaction ◽  
Tank System ◽  
Coastal Space

For better utilization of ocean and coastal space, hydrocarbon products can be stored in the floating tanks, which can be enclosed by barge system. The barge system can be moored through pile foundations. The tanks are moored through marine fenders connected to barges. In the system, hydrodynamic and mechanical interaction problems are involved. Different scenarios including two barge, three barge and four barge systems are investigated. In addition, one tank plus four barge system are also studied. Hydrodynamic interactions between different bodies are firstly studied to investigate the significance of interaction. Different barge configurations are then considered in terms of mechanical interaction significance. Tank dynamic responses with and without hydrodynamic interaction are evaluated.

scholarly journals Dynamic response analysis of the integrated station-bridge elevated station under the pile-soil interaction

2020 ◽  
Vol 165 ◽  
pp. 04081
Author(s):  
Shuqi Zhang ◽  
Jin Li ◽  
Jingyuan Li ◽  
Jiaolei Zhang
Keyword(s):  
Dynamic Response ◽  
Interaction Model ◽  
Dynamic Responses ◽  
Response Analysis ◽  
Transverse Displacement ◽  
Rigid Foundation ◽  
Base Shear ◽  
Maximum Displacement ◽  
Finite Element Software ◽  
Mechanical Models

In order to study the dynamic response of the integrated station-bridge structure under the pile-soil interaction, a model was established by finite element software for dynamic analysis. According to a practical project, two mechanical models are established: one is the pile-soil interaction model, the other is the rigid foundation model. The dynamic responses of the two models were analyzed respectively, and then the results were compared. The results show that: the structure with pile-soil interaction has a longer period and higher flexibility; Under the action of frequently occurred earthquakes, the maximum displacement of the structure with pile-soil interaction increases and the base shear decreases; Under the action of seldomly occurred earthquakes, the structural displacement and base shear under the pile-soil interaction become larger, and the transverse displacement is more affected than the longitudinal displacement. It is concluded that: the assumption of rigid foundation makes the result more conservative, and the influence of pile-soil interaction cannot be ignored in seismic response analysis.

Earthquake Response Analysis of Bridge Piers in Deep Water under Hydrodynamic Pressure Action

2012 ◽  
Vol 256-259 ◽  
pp. 1480-1483
Author(s):  
Xin Huang ◽  
Zhao Wei Huang ◽  
Xue Ying Hu ◽  
Hao Liang Cai ◽  
Lin Qi ◽  
...  
Keyword(s):  
Deep Water ◽  
Interaction Analysis ◽  
Hydrodynamic Pressure ◽  
Wave Theory ◽  
Dynamic Interaction ◽  
Bridge Pier ◽  
Dynamic Responses ◽  
Bridge Piers ◽  
Response Analysis ◽  
Earthquake Excitation

In order to ensure safety of long and huge bridges in deep water under earthquake action, it is significance to consider water and bridge pier dynamic interaction. Analysis method of water-bridge pier dynamic interaction under earthquake excitation is established using radiation wave theory, and earthquake induced hydrodynamic pressure apply program is complied. Considering different earthquake wave input, earthquake induced hydrodynamic pressure influence on dynamic responses of bridge pier in deep water is further studied. The results indicate that: Dynamic response of bridge pier in deep water is augmented because of hydrodynamic pressure action. Earthquake induced hydrodynamic pressure influence on seismic responses of bridge piers in deep water will change with different input earthquake wave.

Dynamic Response Analysis of a Floating Offshore Wind Turbine During Severe Typhoon Event

2013 ◽  
Author(s):  
Tomoaki Utsunomiya ◽  
Iku Sato ◽  
Shigeo Yoshida ◽  
Hiroshi Ookubo ◽  
Shigesuke Ishida
Keyword(s):  
Dynamic Response ◽  
Wind Turbine ◽  
Dynamic Responses ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Response Analysis ◽  
Dynamic Response Analysis ◽  
Floating Offshore Wind Turbine ◽  
Demonstration Experiment ◽  
Typhoon Event

In this paper, dynamic response analysis of a Floating Offshore Wind Turbine (FOWT) with Spar-type floating foundation is presented. The FOWT mounts a 100kW down-wind turbine, and is grid-connected. It was launched at sea on 9th June 2012, and moored on 11th for the purpose of the demonstration experiment. During the experiment, the FOWT was attacked by severe typhoon events twice. Among them, Sanba (international designation: 1216) was the strongest tropical cyclone worldwide in 2012. The central atmospheric pressure was 940 hPa when it was close to the FOWT, and the maximum significant wave height of 9.5m was recorded at the site. In this paper, the dynamic responses of the platform motion, the stresses at the tower sections and the chain tensions during the typhoon event, Sanba (1216), have been analyzed, and compared with the measured data. Through the comparison, validation of the numerical simulation tool (Adams with SparDyn developed by the authors) has been made.

Sign in / Sign up

Export Citation Format

Share Document