scholarly journals Numerical simulation of pounding damage to caisson under storm surge

2018 ◽  
Vol 38 ◽  
pp. 03046
Author(s):  
Chen Yu
Keyword(s):  
Numerical Simulation ◽  
Storm Surge ◽  
Failure Mode ◽  
Structural Model ◽  
Time History ◽  
Element Model ◽  
Wave Force ◽  
New Method ◽  
Wave Direction ◽  
Force Time

In this paper, a new method for the numerical simulation of structural model is proposed，which is employed to analyze the pounding response of caissons subjected to storm surge loads．According to the new method，the simulation process is divided into two steps. Firstly, the wave propagation caused by storm surge is simulated by the wave-generating tool of Flow-3D, and recording the wave force time history on the caisson. Secondly，a refined 3D finite element model of caisson is established，and the wave force load is applied on the caisson according to the measured data in the first step for further analysis of structural pounding response using the explicit solver of LSDYNA. The whole simulation of pounding response of a caisson caused by “Sha Lijia” typhoon is carried out. The results show that the different wave direction results in the different angle caisson collisions, which will lead to different failure mode of caisson, and when the angle of 60 between wave direction and front/back wall is simulated, the numerical pounding failure mode is consistent with the situation.

Wave Induced Pressures on Pipelines Near a Sloping Boundary Due to Regular Waves

2002 ◽  
Author(s):  
K. A. Roopsekhar ◽  
V. Sundar
Keyword(s):  
Time History ◽  
Wave Direction ◽  
Regular Waves ◽  
Scattering Parameter ◽  
Similarity Parameter ◽  
Experimental Procedure ◽  
Sloping Bed ◽  
Model Setup ◽  
Force Time ◽  
Wave Induced

The hydrodynamic pressures due to regular waves around the circumference of a pipeline near a sloping rigid bed and placed parallel to the wave direction have been measured. The pressures were integrated to obtain the force time history, from which the peak horizontal and vertical forces were evaluated. The effects of relative clearance of pipe from the bed and its relative position from the toe of the sloping bed on the pressures and forces on the pipeline as a function scattering parameter and wave steepness are reported. The reflection characteristics of the sloping bed in the presence of the pipeline are reported as a function of surf similarity parameter and compared with the results from existing literature. The details of the model setup, experimental procedure, results and discussion are presented in this paper.

scholarly journals Stress Characteristics and Overload Failure Analysis of Cemented Sand and Gravel Dam in Naheng Reservoir

Open Physics ◽  
2019 ◽  
Vol 17 (1) ◽  
pp. 950-959
Author(s):  
Zhaoqiang Wang ◽  
Xin Chen
Keyword(s):  
Numerical Simulation ◽  
Failure Mode ◽  
Model Test ◽  
Structural Model ◽  
Test Method ◽  
Distribution Law ◽  
Dead Weight ◽  
Cemented Sand ◽  
Stress And Deformation ◽  
Sand And Gravel

Abstract On the basis of the Naheng Reservoir Project, the stress, strain, and deformation of Naheng Reservoir cemented sand and gravel dam are simulated numerical simulation and structural model test. The stress and deformation laws of the dam under the combined load of dead weight and normal water level are analyzed using the structural model test method. Compared with the finite element numerical simulation, the results reflect the stress and deformation distribution law of the dam. Then, the failure mode of the cemented sand and gravel dam can be visualized by using the water load overload method to conduct the structural model failure test, and the failure mode and failure mechanism of the cemented sand and gravel dam can be discussed. The research results lay a foundation for further determining the safety degree analysis of cemented sand and gravel dam.

A Scheme of a Knowledge Based System for Optimal Modelling and Design of Robots

1994 ◽  
Author(s):  
Michael Lawo
Keyword(s):  
Structural Model ◽  
Natural Frequencies ◽  
Structural Parameters ◽  
Time History ◽  
Element Model ◽  
Identification Problem ◽  
Optimization Method ◽  
Knowledge Based System ◽  
Knowledge Based ◽  
History Of

Abstract Based on a finite element model the deformations and vibrations of a robot structure are calculated for different configurations (layouts). The results of the analysis are verified by measuring the corresponding deformations and velocities. The time history of velocities at different points of the structure in test positions is recorded. Out of the time history by modal analysis the natural frequencies are determined. The structural model is checked by the comparison of corresponding analysed and measured values A nonlinear optimization method with the structural parameters as variables of the model is used for the solution of this identification problem. The result is a verified and sufficient structural model of the real structure. Out of the experiences a knowledge based system for the modelling and simulation of robot structures is conceived. The concept of the system is presented.

scholarly journals Dynamic effects induced by the impact of debris flows on protection barriers

2018 ◽  
Vol 10 (1) ◽  
pp. 116-131 ◽  
Author(s):  
Maddalena Marchelli ◽  
Valerio De Biagi
Keyword(s):  
Impact Force ◽  
Time History ◽  
Element Model ◽  
Interaction Force ◽  
Accurate Analysis ◽  
Vibration Period ◽  
Time Histories ◽  
Mode Vibration ◽  
Force Time ◽  
The Impact

Debris flow is a transient phenomenon that causes large disasters. Retaining systems, whose design is still nowadays a crucial issue, can mitigate this risk. Multiple surges can arise during this phenomenon; thus, an accurate analysis might consider the impact force time histories rather than only its maxima. The aim of this work is to analyze the effects of the interaction between the debris and the barrier during one surging phenomenon. A discrete element model models the granular motion and the interaction between the debris and a rigid open barrier set at the end of the channel. The estimated interaction force time history is then used as input impact force for the dynamic structural analyses of the piles. A total of 12 different structural sections are adopted and the internal forces at the base are critically compared. It results that the first mode vibration period is the parameter that largely affects the behavior of the piles.

Hydrodynamic Analysis of Oil Storage Vessels for National Strategic Petroleum Reserve

2011 ◽  
Vol 291-294 ◽  
pp. 2541-2551
Author(s):  
Gang Jun Zhai ◽  
Yong Cheng ◽  
Wen Hua Wang ◽  
Yi Huang
Keyword(s):  
Incident Wave ◽  
Vertical Direction ◽  
Time History ◽  
Wave Force ◽  
Mooring System ◽  
Wave Direction ◽  
Storage Vessel ◽  
Oil Storage ◽  
Motion Responses ◽  
Incident Wave Direction

This paper expatiates hydrodynamic time-domain analysis on strategic oil storage vessels in free floating condition or with dolphin-fender mooring system by means of AQWA numerical software. The results indicate that motion responses of the oil storage vessel with dolphin-fender mooring have improved significantly. The time-history of wave diffraction forces in incident wave direction are basically consistent between the free floating and moored condition. However, in vertical direction of incident wave, the diffraction wave force of the oil storage vessel in free floating condition is obviously different from that with mooring system, which is the result of the coupling interaction between dolphin and vessels. Mooring forces include fender reaction and cable tension, as for which dominate, it depend on evocable motion responses about incident wave direction.

Dynamic Response Research of Ship/Jacket Platform Collision

2009 ◽  
Author(s):  
Jin Gan ◽  
Weiguo Wu ◽  
Jin Pan ◽  
Huanxiang Sun ◽  
Mengwei Zhu
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Dynamic Response ◽  
Finite Element Model ◽  
Time History ◽  
Element Model ◽  
Jacket Platform ◽  
Finite Element Numerical Simulation ◽  
Simplified Finite Element Model ◽  
Local Deformations

In this paper, a new simplified finite element model is proposed for ship-jacket platform collision. This model can achieve all kinds of concerned parameters and time history curves through once calculation. This paper also discusses the effect of stain rate in ship-platform collision. On the basis of the above work, finite element numerical simulation of ship-platform collision is carried out. Some important results such as collision forces, stress, local deformations, distribution of various energies and displacement of platform are discussed. At last, some useful conclusions are achieved.

Numerical Simulation of Consecutive Multiple Lateral Impact on the Reinforced Concrete Pier

2019 ◽  
Author(s):  
Shuai Yang ◽  
Xiao-zhou Xia ◽  
Qing Zhang ◽  
Xue-gang Wang ◽  
Zong-quan Ying
Keyword(s):  
Numerical Simulation ◽  
Reinforced Concrete ◽  
Impact Resistance ◽  
Time History ◽  
Element Model ◽  
Lateral Impact ◽  
Analysis Strategy ◽  
Damage Constitutive Model ◽  
Multiple Impact ◽  
Explicit Dynamic

Abstract The consecutive multiple impact resistance of reinforced concrete pier column becomes the most concern in the engineering field. Numerical simulation the process of consecutive multiple lateral impacts is the necessary measures to master the internal mechanism. The fine 3D finite element model is established combining solid element and beam element. The dynamic damage constitutive model of concrete is developed. To react to problem of calculative efficiency and damage accumulation effect, the reduced integration method and full restart analytical method of explicit dynamic analysis strategy is taken using element failure criterion. The translation process of the system energy, the time history value of impact mass acceleration and strain gauge and failure mode of the reinforced concrete pier are compared with the experiment results. The feasibility of the modelling and the validity of the analysis strategy are validated. This study can provide computation basis for research of reinforced concrete structures under consecutive multiple impact.

Study on Suspended Mass Pendulums for Vibration Control of Transmission Tower under Seismic Excitation

2012 ◽  
Vol 446-449 ◽  
pp. 3323-3327
Author(s):  
Li Tian ◽  
Wen Feng Li ◽  
Zi Long Wang
Keyword(s):  
Numerical Simulation ◽  
Vibration Control ◽  
Passive Control ◽  
Simulation Analysis ◽  
Engineering Application ◽  
Time History ◽  
Element Model ◽  
Seismic Excitation ◽  
Transmission Tower ◽  
Tower Vibration

In order to research the effectiveness of passive control on transmission tower vibration control under seismic excitation, suspended mass pendulum (SMP) is carried out in this study. Based on the mechanism and equation of earthquake vibration control, earthquake induced vibration control for transmission tower model with suspended mass pendulums was performed by using numerical simulation. Using SAP2000 software, three-dimensional finite element model of a transmission tower is created, and seismic records are selected by different site soils. Typical time history curves and the maximum responses of displacement, axis force, shear force and moment of the transmission tower without and with suspended mass pendulums are obtained by numerical simulation analysis. The results show that the SMP is very effective in mitigating tower vibration, and the method can be a reference for practice engineering application.

scholarly journals Phase manipulation and the harmonic components of ringing forces on a surface-piercing column

2014 ◽  
Vol 470 (2168) ◽  
pp. 20130847 ◽  
Author(s):  
C. J. Fitzgerald ◽  
P. H. Taylor ◽  
R. Eatock Taylor ◽  
J. Grice ◽  
J. Zang
Keyword(s):  
Water Waves ◽  
Fourier Transforms ◽  
Time History ◽  
Wave Force ◽  
Separation Method ◽  
Coastal Protection ◽  
Time Histories ◽  
Local Wave ◽  
Harmonic Components ◽  
Force Time

A general phase-based harmonic separation method for the hydrodynamic loading on a fixed structure in water waves of moderate steepness is proposed. An existing method demonstrated in the experimental study described by Zang et al. (Zang et al. 2010 In Proc. Third Int. Conf. on Appl. of Phys. Modelling to Port and Coastal Protection. pp. 1–7.) achieves the separation of a total diffraction force into odd and even harmonics by controlling the phase of incident focused waves. Underlying this method is the assumption that the hydrodynamic force in focused waves possesses a Stokes-like structure. Under the same assumption, it is shown here how the harmonic separation method can be generalized, so that the first four sum harmonics can be separated by phase control and linear combinations of the resultant time-histories. The effectiveness of the method is demonstrated by comparisons of the Fourier transforms of the combined time-histories containing the harmonics of interest. The local wave elevations around the focus time are also visualized for the first three harmonics in order to reveal the local dynamics driving components within the wave force time-history.

The Concept of the Optimum Alignment of Discharge Pipelines Due to the Minimization of the Wave Forces

1992 ◽  
Vol 25 (9) ◽  
pp. 211-216
Author(s):  
A. Akyarli ◽  
Y. Arisoy
Keyword(s):  
Wave Height ◽  
Wave Force ◽  
Wave Forces ◽  
Wave Direction ◽  
Incoming Wave ◽  
Pipeline Route ◽  
Optimum Alignment ◽  
The Cost ◽  
Resultant Wave

As the wave forces are the function of the wave height, period and the angle between the incoming wave direction and the axis of the discharge pipeline, the resultant wave force is directly related to the alignment of the pipeline. In this paper, a method is explained to determine an optimum pipeline route for which the resultant wave force becomes minimum and hence, the cost of the constructive measures may decrease. Also, the application of this method is submitted through a case study.

Sign in / Sign up

Export Citation Format

Share Document