scholarly journals Similarity Law between Centrifuge Scale Test and Prototype Underwater Explosion

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Shang Ma ◽  
Yeqing Chen ◽  
Zhenqing Wang ◽  
Jianhui Wang ◽  
Linmei Lyu ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Steel Plate ◽  
Hydraulic Structure ◽  
Underwater Explosion ◽  
Prototype Model ◽  
Test Scheme ◽  
Scaled Model ◽  
Similarity Relationship ◽  
Prototype Test ◽  
Scale Test

Shock wave and bubble pulsation caused by underwater explosion destroy the hydraulic structure. However, the realization of the underwater explosion prototype test is restricted by many factors, such as the site environment. Furthermore, the repeatability of the test scheme is not strong. The centrifuge scale test provides a new way of studying the damage degree of the structure under the action of underwater explosion. The similarity relationship refers to the bridge between the scaled model and the prototype, which cannot achieve complete similarity in practice. The centrifuge-scaled model test is performed by increasing the acceleration of a certain multiple. Meanwhile, the model reduces the corresponding ratio in the geometric layout to achieve the geometric similarity with the prototype test. Therefore, the applicability of the centrifuge scaling method in the study of the dynamic response of the structure in underwater explosion needs to be explored further. In this work, the underwater explosion scaling test numerical model for 1 g RDX (equivalent to 1.62 g TNT) charge under different centrifugal acceleration conditions is established, and the calculation results of underwater pressure and dynamic response of the steel plate are compared with the centrifuge test results. A prototype model is established to study the similarity relationship between the centrifuge scale test and the prototype model when the steel plate structure is in the stage of small deformation and linear elasticity. The application of the similarity ratio in the scale test of underwater explosion the centrifuge is discussed. The application of the centrifuge in the study of the failure response of the hydraulic structure in underwater explosion is expanded by establishing the model and comparing with the experimental results.

Transient Response of the Steel Plate to Underwater Explosion Bubble

2020 ◽  
Author(s):  
Yingyu Chen ◽  
Xiongliang Yao ◽  
Liangtao Liu ◽  
Ning Gan ◽  
Xiongwei Cui
Keyword(s):  
Dynamic Response ◽  
Physical Process ◽  
Bubble Growth ◽  
Steel Plate ◽  
Permanent Deformation ◽  
Three Dimensional ◽  
Underwater Explosion ◽  
Complex Problem ◽  
Bubble Collapse ◽  
The Finite Element Method

Abstract In this paper, a coupling eulerian langarian method (CEL) is used to study the interaction between a collapsing underwater explosion bubble and a steel plate. The VOF method is used to simulate the physical process of bubble growth, contraction and collapse, while the finite element method is used to calculate dynamic response of the steel plate. By establishing the three dimensional numerical model, the study reveals the interesting insights into the complex problem of interaction a underwater explosion bubble and a steel plate, including the physical process of bubble growth, contraction and collapse, the dynamic response of the steel plate, as well as the wall pressure induced by the bubble dynamic. The results indicate that the elastic-plastic plate will generate permanent deformation loaded by the water jet; owing to the deformation of the nearby structure, the bubble shows as a “hazel” in the bubble contraction phase and forms toroidal jet which leads the bubble into several toroidal bubbles in the bubble collapse phase. This paper aim at proposing an effective numerical method which can be useful for the problem of strong interaction between bubble and structure.

scholarly journals Dynamic Response of Composite Steel Lining Structure under Blast Loading

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Desen Kong ◽  
Yu Xu ◽  
Cheng Song
Keyword(s):  
Dynamic Response ◽  
Emergency Response ◽  
Steel Plate ◽  
Axial Stress ◽  
Subway Tunnel ◽  
Analysis Software ◽  
Research Results ◽  
Protection Method ◽  
Lining Structure ◽  
Composite Steel

According to the advantages of high tensile resistance and high shear strength of composite steel plate, a new antiexplosion protection method of composite steel plate lining structure is put forward. The numerical model of explosion impact of subway tunnel with composite steel plate lining structure was established by dynamic analysis software. The transient dynamic response of lining structure with the composite steel plate was simulated when explosion occurred. The research results show that the influence of explosive quantity on each point of composite steel plate lining structure is different and the change of acceleration near the centre of the detonation source is generally greater than the multiple of the increase of explosive quantity. The increase of velocity and displacement is basically consistent with the quantity of explosive. The influence of axial stress on the lining structure is the least, and the influence of the lining structure is greater in the y-direction than in the x-direction. The research results can provide the plan and basis for the emergency response of the subway tunnel.

scholarly journals Foundations, Design, and Dynamic Performance of Wind Turbines: Overview and Challenges in Sudan

2021 ◽  
Vol 9 (1) ◽  
pp. 96-103
Author(s):  
Ruba Asim Hamza ◽  
Amged Osman Abdelatif
Keyword(s):  
Dynamic Response ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Structural Damage ◽  
Renewable Energy Sources ◽  
Dynamic Performance ◽  
Scaled Model ◽  
Static Loads ◽  
Design Loads ◽  
Foundation Type

Sudan is one of the developing countries that suffers from a lack of electricity, where the national electrification rate is estimated at 38.5%. In order to solve this problem, it is possible to use renewable energy sources such as wind energy. Beside many aspects to be considered at the design of wind turbine foundations, more attention should be given to the geotechnical part. There are many types of foundations for wind turbines. The foundation must satisfy two design criteria: 1) It should be safe against bearing failure in soils under design loads and settlements during the life of the structure must not cause structural damage; 2) In addition to static loads, wind turbine foundations loads are extremely eccentrically and the loading is usually highly dynamic. Therefore, the selection of foundation type should consider these two criteria taking into account the nature and magnitude of these loads. This paper presents a review of different types of wind turbine foundations of focusing on on-shore wind turbine foundation types and the dynamic response of wind turbine. The paper also demonstrate experimentally the dynamic response of the wind turbines using wind tunnel facility test on a scaled model.  

scholarly journals Evaluation of Infiltration Rainwater Drainage (IRD) System with Fully 3-D Numerical Simulation Approach

2021 ◽  
Vol 11 (19) ◽  
pp. 9144
Author(s):  
Jungkyu Ahn ◽  
Seongil Yeom ◽  
Sungwon Park ◽  
Thi Hoang Thao Nguyen
Keyword(s):  
Water Scarcity ◽  
Surface Runoff ◽  
Urban Areas ◽  
Model Simulation ◽  
Three Dimensional ◽  
Lag Time ◽  
Prototype Model ◽  
Scaled Model ◽  
Runoff Decrease ◽  
Peak Runoff

Water scarcity can mean scarcity in availability due to physical shortage, or scarcity in access due to the failure of institutions to ensure a continuously regular supply or due to a lack of adequate infrastructure. Water scarcity will be exacerbated as rapidly growing urban areas place heavy pressure on water resources. To solve these problems, various solutions have been applied, but a fundamental solution has not been applied. Recently, a researched and developed infiltration rainwater drainage (IRD) system is being applied with consideration of its applicability. In this study, features of surface runoff and infiltration according to various flow patterns were analyzed using a three-dimensional CFD (Computational Fluid Dynamics) model for calculating water flow in the IRD system. To estimate the optimal setup, a permeability test and scaled model simulation were performed. The runoff characteristics of the IRD system with respect to rainfall intensity and duration were analyzed with dimensionless variables. With the prototype model, the drainage characteristics of the IRD system were analyzed over time using the hydrological curves. From the simulated results, it was found that the IRD system analyzed in this study was appropriate in the field by comparative analysis with the existing system based on peak runoff, internal storage, and lag time. Therefore, by applying the IRD system in the future, it is expected that the IRD has benefits, such as delayed lag time, surface runoff decrease, and an attenuation of the peak runoff.

scholarly journals Dynamic Response Prediction of Underwater Explosion Vessels

2020 ◽  
Vol 453 ◽  
pp. 012040
Author(s):  
Linna Li ◽  
Yanfei Hu ◽  
Chenchen Fang ◽  
Yue You ◽  
Kai Liu ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Underwater Explosion ◽  
Response Prediction

Underwater explosion in centrifuge Part II: Dynamic responses of defensive steel plate

2017 ◽  
Vol 60 (12) ◽  
pp. 1941-1957 ◽  
Author(s):  
Yuan Long ◽  
HongYuan Zhou ◽  
XiangQian Liang ◽  
Ge Song ◽  
ZuYu Chen ◽  
...  
Keyword(s):  
Steel Plate ◽  
Underwater Explosion ◽  
Dynamic Responses

Parametric Study of Tendon Profiles in Prestressed Steel Plate Girder

2002 ◽  
Vol 5 (2) ◽  
pp. 75-85 ◽  
Author(s):  
G. N. Ronghe ◽  
L. M. Gupta
Keyword(s):  
Carrying Capacity ◽  
Steel Plate ◽  
Steel Structures ◽  
Prototype Model ◽  
Load Carrying Capacity ◽  
Prestressing Steel ◽  
Analysis And Design ◽  
Prestressing Force ◽  
Load Carrying ◽  
Plate Girder

The concept of prestressing steel structures has only recently been widely considered, despite a long and successful history of prestressing concrete members. Several analytical studies of prestressed steel plate girder were reported in the literature, but much of that work was not studied with reference to different parameters like tendon profile, eccentricity, partial span to full span ratio, prestressing force, load carrying capacity etc. associated with prestressing. This paper examines analytically a comparative study of various tendon configurations and prestressing parameters on over all analysis and design of prestressed steel plate girder. The output from the computer Program for analysis and design of steel plate girder prestressed with different tendon configurations are compared among each other. As a Case-study, a prototype model of Prestressed Steel Testing Frame with straight tendon has been designed, constructed and tested in the laboratory for its safe load carrying capacity and maximum deflection.

Model Tests on the Long-Term Dynamic Performance of Offshore Wind Turbines Founded on Monopiles in Sand

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Zhen Guo ◽  
Luqing Yu ◽  
Lizhong Wang ◽  
S. Bhattacharya ◽  
G. Nikitas ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Wind Turbines ◽  
Model Tests ◽  
Offshore Wind ◽  
Frequency Change ◽  
Test Results ◽  
Scaled Model ◽  
Structural Dynamic ◽  
Offshore Wind Turbines

The dynamic response of the supporting structure is critical for the in-service stability and safety of offshore wind turbines (OWTs). The aim of this paper is to first illustrate the complexity of environmental loads acting on an OWT and reveal the significance of its structural dynamic response for the OWT safety. Second, it is aimed to investigate the long-term performance of the OWT founded on a monopile in dense sand. Therefore, a series of well-scaled model tests have been carried out, in which an innovative balance gear system was proposed and used to apply different types of dynamic loadings on a model OWT. Test results indicated that the natural frequency of the OWT in sand would increase as the number of applied cyclic loading went up, but the increasing rate of the frequency gradually decreases with the strain accumulation of soil around the monopile. This kind of the frequency change of OWT is thought to be dependent on the way how the OWT is cyclically loaded and the shear strain level of soil in the area adjacent to the pile foundation. In this paper, all test results were plotted in a nondimensional manner in order to be scaled up to predict the consequences for prototype OWT in sandy seabed.

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