A Fundamental Study on Collision of a Tsunami Drifting Objects Against Structures Using MPS Method and FEM

2018 ◽  
Author(s):  
Koichi Masuda ◽  
Tomoki Ikoma ◽  
Daichi Murata ◽  
Hiroaki Eto ◽  
Akihiro Matsuoka ◽  
...  
Keyword(s):  
Finite Element ◽  
Large Scale ◽  
Steel Structure ◽  
Simulation Method ◽  
Coastal Areas ◽  
Numerical Calculations ◽  
Fundamental Study ◽  
Mps Method ◽  
Acrylic Plate ◽  
The Impact

The large-scale tsunami generated by the Great East Japan Earthquake on March 11, 2011 caused a great deal of damage. In addition to tsunami hydrodynamic forces, loads generated by drifting objects such as ships and cars can cause destruction in coastal areas. As such, impact forces due to collisions of drifting objects are an important consideration in the design and planning of structures in coastal areas. Depending on the size of the drifting object, it is difficult to evaluate the effect of the impact force at the time of collision through tank experiments. Therefore, it is necessary to develop a numerical simulation method that can reasonably evaluate such effects. Such a method must consider the nonlinear interactions among drifting objects, a fluid, and fixed structures. In the present study, we used the moving particle semi-implicit (MPS) and finite element methods to calculate the effect of collisions between drifting objects and structures, and then verified the results experimentally. The MPS method was applied to calculate the loads and pressures due to the collisions. These results were then used to simulate the deformation of the structure using the finite element method. A tank experiment was then conducted in order to confirm the accuracy of the numerical calculations. The deformation of a rod-shaped steel structure was measured following collision with a floating acrylic plate. The experimental results confirmed the accuracy of the numerical calculations.

Vulnerability of coastal areas to increased aquifer saturation due to climate change

2021 ◽  
Author(s):  
Alexandre Gauvain ◽  
Ronan Abhervé ◽  
Jean-Raynald de Dreuzy ◽  
Luc Aquilina ◽  
Frédéric Gresselin
Keyword(s):  
Climate Change ◽  
Sea Level ◽  
Large Scale ◽  
Regional Scale ◽  
Drainage System ◽  
Hydrological Regime ◽  
Coastal Areas ◽  
Western Coast ◽  
Study Sites ◽  
The Impact

<p>Like in other relatively flat coastal areas, flooding by aquifer overflow is a recurring problem on the western coast of Normandy (France). Threats are expected to be enhanced by the rise of the sea level and to have critical consequences on the future development and management of the territory. The delineation of the increased saturation areas is a required step to assess the impact of climate change locally. Preliminary models showed that vulnerability does not result only from the sea side but also from the continental side through the modifications of the hydrological regime.</p><p>We investigate the processes controlling these coastal flooding phenomena by using hydrogeological models calibrated at large scale with an innovative method reproducing the hydrographic network. Reference study sites selected for their proven sensitivity to flooding have been used to validate the methodology and determine the influence of the different geomorphological configurations frequently encountered along the coastal line.</p><p>Hydrogeological models show that the rise of the sea level induces an irregular increase in coastal aquifer saturations extending up to several kilometers inland. Back-littoral channels traditionally used as a large-scale drainage system against high tides limits the propagation of aquifer saturation upstream, provided that channels are not dominantly under maritime influence. High seepage fed by increased recharge occurring in climatic extremes may extend the vulnerable areas and further limit the effectiveness of the drainage system. Local configurations are investigated to categorize the influence of the local geological and geomorphological structures and upscale it at the regional scale.</p>

Fundamental Study on Elastic Behavior of Large-Scale Floating Coal Stockyard

2016 ◽  
Author(s):  
Hiroaki Eto ◽  
Chiaki Sato ◽  
Koichi Masuda ◽  
Tomoki Ikoma ◽  
Tomoyuki Kishida ◽  
...  
Keyword(s):  
Mass Distribution ◽  
Large Scale ◽  
Asia Pacific ◽  
Elastic Behavior ◽  
Loading Conditions ◽  
Floating Structure ◽  
Fundamental Study ◽  
Local Rigidity ◽  
East Kalimantan ◽  
The Impact

This paper proposes a large-scale floating coal stockyard (LFCS) and discusses its elastic behavior. Indonesia has recently become the main country supplying coal in the Asia-Pacific region. However, there is concern that export to Japan will decrease as coal demand increases. Therefore, the trend of coal transport in Indonesia is a very important matter in ensuring the continued stable import of coal to Japan. It is difficult for bulk carriers to traverse the shallow terrain of the seabed of the Markham River in East Kalimantan to reach coastal areas. Additionally, an LFCS can be operated as a relay base for barges, and large coal carriers have been proposed for use in offshore areas. The LFCS is capable of loading, storing, and offloading coal. Installing an LFCS offshore Kalimantan is expected to improve coal transport productivity in the region. Under such circumstances, the design plan proposed in this paper can simultaneously perform independent loading and unloading without interference. The partial mass distribution and local rigidity of the LFCS varies depending on the coal loading conditions. In addition, because the structure has a planar shape, the response of the LFCS showed elastic behavior. Design example of such a huge floating structure with the great difference of the displacement is unparalleled, it is very important to clarify a design fundamental subject. The objectives of this study are to provide a preliminary LFCS design and investigate the impact of varying the mass distribution and local rigidity on not only the distribution of the distortion and internal stress but also on the dynamic hydroelastic motion of the LFCS when it is impacted by waves. Therefore, the wave response of the LFCS was analyzed under different loading conditions.

Influence of Oriented Perforation Design on Refracture Reorientation: Simulation and Experiment

2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Minhui Qi ◽  
Mingzhong Li ◽  
Tiankui Guo ◽  
Chunting Liu ◽  
Song Gao ◽  
...  
Keyword(s):  
Hydraulic Fracturing ◽  
Large Scale ◽  
Simulation Models ◽  
Fracture Initiation ◽  
Simulation Method ◽  
Induced Stress ◽  
Study Results ◽  
Simulation Results ◽  
Fracturing Experiments ◽  
The Impact

The oriented perforating is the essential technique to guide the refracture reorientation, but the influence of the oriented perforation design on the refracture steering radius is still unclear. In this paper, the factors influencing the refracture reorientation were studied by simulation models and experiments. The effects of initial fracture, well production, and perforations on the refracture initiation and propagation were analyzed. Three-dimensional finite element models were conducted to quantify the impact of perforation depth, density, and azimuth on the refracture. The large-scale three-axis hydraulic fracturing experiments guided by oriented perforations were also carried out to verify the fracture initiation position and propagation pattern of the simulation results. The research results showed that perforations change the near-wellbore induced stress distribution, thus changing the steering radius of the refracture. According to the simulation results, the oriented perforation design has a significant influence on the perforation guidance effect and refracture characteristics. Five hydraulic fracturing experiments proved the influence of perforating parameters on fracture initiation and morphology, which have a right consistency between the simulation results. This paper presents a numerical simulation method for evaluating the influence of the refracture reorientation characteristics under the consideration of multiple prerefracturing induced-stress and put forward the oriented perforation field design suggestions according to the study results.

Study of Sub-Synchronous Control Interaction (SSCI) Based on the Test Signal Method

2014 ◽  
Vol 989-994 ◽  
pp. 2980-2984
Author(s):  
Ben Feng Gao ◽  
Jin Liu ◽  
Shu Qiang Zhao
Keyword(s):  
Transmission Lines ◽  
Large Scale ◽  
Simulation Method ◽  
Test Signal ◽  
Equivalent Model ◽  
Series Compensation ◽  
Synchronous Control ◽  
The Impact ◽  
Signal Method ◽  
Control Interaction

Large-scale wind turbine generators with power electronic converters that operate near series compensated transmission lines are susceptible to un-damped sub-synchronous oscillations. This sub-synchronous oscillation is called Sub-synchronous Control Interaction (SSCI). Based on PSCAD / EMTDC simulation platform the establishment of Double Fed Induction Generator (DFIG) equivalent inverter controlled sources and network model, and verify the correctness of the equivalent model. Analysis the impact of series compensation and rotor-side converter PI parameters characteristic of the SSCI based on test signal method and time-domain simulation method. The results show that increasing the degree of series compensation , inner gain constant increases and inner integral time decreases will help increase SSCI, outer ring of PI parameters has little effect on the SSCI .

scholarly journals Development of impact attenuator analysis tools in crash scenario using Euler method and finite element analysis

2022 ◽  
Vol 69 (1) ◽  
Author(s):  
Malik Athafarras ◽  
Djati Wibowo Djamari ◽  
Muhamad Rausyan Fikri ◽  
Bentang Arief Budiman ◽  
Farid Triawan ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Simulation Method ◽  
Euler Method ◽  
Element Analysis ◽  
Time Model ◽  
Crash Simulation ◽  
Car Crash ◽  
Element Simulation ◽  
The Impact

AbstractThe problem considered in this work is the development of simulation method for simulating car crash which utilizes simple car—impact attenuator model developed in MATLAB. Usually, car crash simulation is done using full finite element simulation which could take hours or days depending on the model size. The purpose of proposed method is to achieve quick results on the car crash simulation. Past works which utilizes simple car—impact attenuator model to simulate car crash use continuous time model and the impact attenuator parameter is obtained from the experimental results. Different from the related works, this work uses discrete time model, and the impact attenuator parameter is obtained from finite element simulation. Therefore, the proposed simulation method is not only achieving quick simulation results but also minimizing the cost and time in obtaining the impact attenuator parameter. The proposed method is suitable for parametric study of impact attenuator.

Finite element analysis and improved design of large-scale belt-conveyor drums

2016 ◽  
Vol 7 (6) ◽  
pp. 724-738
Author(s):  
Athanassios Mihailidis ◽  
George Savaidis ◽  
Emmanouil Bouras ◽  
Emmanouil Athanasopoulos ◽  
Nikolaos Ganavaras ◽  
...  
Keyword(s):  
Finite Element ◽  
Large Scale ◽  
Fatigue Cracks ◽  
Creep Model ◽  
Belt Conveyor ◽  
Content Type ◽  
Operational Life ◽  
Improved Design ◽  
Alternative Designs ◽  
The Impact

Purpose Large-scale belt-conveyor systems are extensively used in open mines to continuously transport bulk material. Conveyor pulleys are critical components and failures have significant financial consequences due to extended downtime. Aiming at increasing their durability, two critical spots are identified: the drum and the welds between end-plates and drum. Alternative designs have been evaluated. The paper aims to discuss these issues. Design/methodology/approach Loads on the driving drum are determined from measurements of the bearing force and the motor power. The friction interaction between belt and drum is described by the creep model and its impact is evaluated by comparing the results obtained for low and typical values of friction coefficient. Alternative designs are analysed using finite element method with optimised variable density mesh. The stress field and the deformations are calculated and evaluated. Findings Friction affects the torque transmission capacity and force distribution, but it is shown that in this case it has almost no impact on the maximum von Mises stress which occurs on the inside surface of the drum; therefore fatigue cracks initiated there, cannot be visually detected. A reinforcing diaphragm is added at the mid-plane to reduce the stress. A new, improved design is proposed to eliminate welds between the end-plates and the drum. Research limitations/implications The new proposed design has to be tested in the field to ultimately validate its higher durability. Originality/value The impact of the friction of the belt on the drum is demonstrated. The reinforcement resulting from a mid-plane diaphragm is quantitatively evaluated and assessed. A new improved pulley design is proposed aiming at significantly increased operational life compared to the one of the current design.

scholarly journals Relationship Between Matrix Cracking and Delamination in CFRP Cross-Ply Laminates Subjected to Low Velocity Impact

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3990 ◽  
Author(s):  
Riming Tan ◽  
Jifeng Xu ◽  
Wei Sun ◽  
Zhun Liu ◽  
Zhidong Guan ◽  
...  
Keyword(s):  
Finite Element ◽  
Large Scale ◽  
Matrix Cracking ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Matrix Cracks ◽  
Impact Location ◽  
The Matrix ◽  
The Impact

The effect of matrix cracking on the delamination morphology inside carbon fiber reinforced plastics (CFRP) laminates during low-velocity impact (LVI) is an open question. In this paper, the relationship between matrix cracking and delamination is studied by using cross-ply laminates. Several methods, including micrograph, C-scan, and visual inspection, were adopted to characterize the damage after LVI experiments. Based on the experimental results, finite element (FE) models were established to analyze the damage mechanisms. The matrix cracking was predicted by the extended finite element method (XFEM) and the Puck criteria, while the delamination was modeled by cohesive elements. It was revealed that the matrix crack in the bottom ply not only promoted the outward propagation of delamination but also contributed to the narrow delamination beneath the impact location. Multiple matrix cracks occurred in the middle ply. The ones close to the plate center initiated the delamination and prevented large-scale delamination beneath the impact location. For the cracks that were far away, no significant effect on delamination was found. In conclusion, the stress redistribution caused by the crack opening determines the delamination.

Rigid Joints Transferring Forces outside Box Columns with Deviation of Column's Location Axis-Finite Element Method Simulation

2014 ◽  
Vol 1065-1069 ◽  
pp. 1101-1105
Author(s):  
Zhong Gen Xu ◽  
Guang Xian Liang ◽  
Wei Ming Chen ◽  
Chang Gen Deng
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Steel Structure ◽  
Finite Element Method Simulation ◽  
Construction Process ◽  
Rigid Joints ◽  
Ultimate Carrying Capacity ◽  
The Impact ◽  
Box Columns ◽  
Element Method

location axis, joints, force-transforming plates, carrying capacityAbstract: Steel structure has been widely used all over the world. In actual construction process, steel structure inevitably has initial defects, which may have bad influences on its performance. Three groups of specimens were designed in this paper to compare the performance of rigid joints transferring forces outside box columns to that of perfect traditional joints and that of traditional joints with uniaxial and biaxial deviation of column's location axis by finite element method program ANSYS. From the analysis of stiffness, yielding capacity, and ultimate carrying capacity, the impact of force-transforming plates can be evaluated. The adding force-transforming plates were helpful to reduce the influence from column imperfect.

Impact of Peak and Valley Period Partition on Load Curve of Distribution System with EV

2013 ◽  
Vol 724-725 ◽  
pp. 1344-1349
Author(s):  
Zhen Fu Zhang ◽  
Xiao Qing Huang ◽  
Bo Xiao
Keyword(s):  
Electric Vehicles ◽  
Distribution System ◽  
Large Scale ◽  
Peak Load ◽  
Simulation Method ◽  
Time Instant ◽  
Start Time ◽  
Load Curve ◽  
Electric Vehicle Charging ◽  
The Impact

Large-scale adoption of electric vehicles may impose impact on grid. In order to formulate the appropriate scheme of time-of-use (TOU) to lower the adverse effect of charging load on the power grid, it is necessary to analyze the impact of the peak-valley period partition on the load curve of distribution system with electric vehicles. The electric vehicle charging load model considering TOU was built according to the statistics of the driving habits. Several scenarios were set according to different period partitions and the changes of the load at start time of valley period, numerical value and moment of peak load and peak-valley differences were analyzed with the Monte Carlo simulation method under those scenarios. The simulation results show that the farther between the time instant of peak load and start moment of valley period the less impact it has on load curve of distribution system.

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