scholarly journals Study on Dynamic Strain Regularity and Influencing Factors of Shallow Buried Metal Pipe under Collapse Impact Load

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Min Wang ◽  
Mingshou Zhong ◽  
Yuan Long ◽  
Kai Ding ◽  
Xingbo Xie ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Impact Load ◽  
Simulation Method ◽  
Dynamic Strain ◽  
Stiffness Ratio ◽  
Buried Pipeline ◽  
Range Analysis ◽  
Buried Pipelines ◽  
Soil Stiffness ◽  
Metal Pipe

With the combination of model experiment and numerical simulation, we explore the effect of collapse height, weight, and pipe-soil stiffness ratio on dynamic strain of shallow buried metal pipe under the collapse impact load. By analyzing the strain at different measuring points of the buried pipeline, the strain law of the buried pipeline under the collapse impact load is obtained. Based on the range analysis and variance significance analysis, it was found that the pipe-soil stiffness ratio has a more significant impact on the dynamic strain of the buried pipeline under impact compared to the collapse height and the weight. Then, the numerical simulation method was used to further analyze the effect of pipe-soil stiffness ratio on the dynamic response of buried pipelines; the following conclusions are drawn: As the stiffness ratio of pipe-soil increases, the plastic stress and strain of the buried pipeline will decrease, and influence of the pipeline by the collapse impact is slighter.

The Dynamic Mechanical Properties Study of Aluminum Alloy Honeycomb Material and its Numerical Simulation

2010 ◽  
Vol 452-453 ◽  
pp. 305-308
Author(s):  
Guang Ping Zou ◽  
Zhong Liang Chang ◽  
Xin Zheng Wang ◽  
Bao Jun Liu ◽  
Si Chen
Keyword(s):  
Mechanical Properties ◽  
Numerical Simulation ◽  
Aluminum Alloy ◽  
Impact Load ◽  
Simulation Method ◽  
Dynamic Mechanical Properties ◽  
Dynamic Strain ◽  
Dynamic Mechanical ◽  
Specific Strength ◽  
Aluminum Alloy Honeycomb

Light weight aluminum alloy honeycomb materials are ideal lightweight structure materials, which have higher specific strength and stiffness, and widely applied in aviation, aerospace, automobile and so on, and also it is an ideal material for damping, buffering, heat insulation and energy absorption. In this paper, the SHPB technique which the aluminum alloy bar diameter is 37mm is used for studying the dynamic mechanics property of the lightweight aluminum alloy honeycomb materials which the diameter is 30mm, and then to study the dynamic mechanical properties of the material, from the results we can see dynamic strain-stress curves can be divided into three phases, elastic phase, stress platform and compaction phase. And the numerical simulation method was used for study the dynamic deformation process of the honeycomb panel material under impact load, and also compare the results with the specimen cell figures which were observed by the microscope.

Numerical Simulation on the Dynamic Response of Buried Pipelines Subjected to Blast Loads

2013 ◽  
Vol 671-674 ◽  
pp. 519-522 ◽  
Author(s):  
Guo Fu Xu ◽  
Zheng Dong Deng ◽  
Fei Fan Deng ◽  
Guo Bin Liu
Keyword(s):  
Numerical Simulation ◽  
Shock Wave ◽  
Dynamic Response ◽  
Buried Pipeline ◽  
Blast Loads ◽  
Buried Pipelines ◽  
Axis Direction ◽  
Ground Shock ◽  
Explosion Center

When the shock wave caused by explosion in geotechnical medium encountered buried pipeline, the buried pipeline may be destroyed. Use the LS-DYNA program to describe the deformation of buried pipelines under explosion ground shock. The results indicate that the process of the stress on pipe is instantaneous, and the back of buried pipelines against explosion center suffers greater instantaneous pulling stress in axis direction. The stress on the pipes, which is brought by the weaponary explosion, is involved with the distance between the pipe and explosion center and the diameter of pipe, among which the former involves greater. And the smaller pipe would get greater shock.

scholarly journals Experimental and Numerical Study on the Strain Behavior of Buried Pipelines Subjected to an Impact Load

2019 ◽  
Vol 9 (16) ◽  
pp. 3284 ◽  
Author(s):  
Feifei Dong ◽  
Xuemeng Bie ◽  
Jiangping Tian ◽  
Xiangdong Xie ◽  
GuoFeng Du
Keyword(s):  
Finite Element ◽  
Impact Load ◽  
Numerical Study ◽  
Scale Model ◽  
Peak Strain ◽  
Buried Pipeline ◽  
Buried Pipelines ◽  
Strain Behavior ◽  
Geological Conditions ◽  
The Impact

Long-distance oil and gas pipelines are inevitably impacted by rockfalls during geologic hazards such as mud-rock flow and landslides, which have a serious effect on the safe operation of pipelines. In view of this, an experimental and numerical study on the strain behavior of buried pipelines under the impact load of rockfall was developed. The impact load exerted on the soil, and the strains of buried pipeline caused by the impact load were theoretically derived. A scale model experiment was conducted using a self-designed soil-box to simulate the complex geological conditions of the buried pipeline. The simulation model of hammer–soil–pipeline was established to investigate the dynamic response of the buried pipeline. Based on the theoretical, experimental, and finite element analysis (FEA) results, the overall strain behavior of the buried pipeline was obtained and the effects of parameters on the strain developments of the pipelines were analyzed. Research results show that the theoretical calculation results of the impact load and the peak strain were in good agreement with the experimental and FEA results, which indicates that the mathematical formula and the finite element models are accurate for the prediction of pipeline response under the impact load. In addition, decreasing the diameter, as well as increasing the wall thickness of the pipeline and the buried depth above the pipeline, could improve the ability of the pipeline to resist the impact load. These results could provide a reference for seismic design of pipelines in engineering.

Numerical Simulation of Upheaval Buckling Using “Intelligent” Backfill Soil Springs

2015 ◽  
Author(s):  
Prigiarto Hokkal Yonatan ◽  
Filip Van den Abeele ◽  
Jean-Christophe Ballard
Keyword(s):  
Numerical Simulation ◽  
New Technique ◽  
Buried Pipeline ◽  
Buried Pipelines ◽  
Upheaval Buckling ◽  
Backfill Soil ◽  
Uplift Resistance ◽  
A New Technique ◽  
Force Equilibrium

Designing the cover height of buried pipelines to prevent them from buckling requires a method that can thoroughly and realistically model the phenomenon. This paper introduces a new technique to assess the risk of upheaval buckling (UHB) by using backfill soil springs (BFSS) to represent the uplift resistance provided by the backfill soil on top of a buried pipeline. This paper investigates the pre-buckling pipeline behavior related to UHB and highlights some of the key parameters governing the analysis. UHB assessment based on a case study was carried out and the results were then compared with those obtained from force-equilibrium methods generally used in the industry. The comparison shows that UHB assessment can be performed more rigorous using BFSS than using force-equilibrium methods. Therefore, using BFSS for UHB assessment improve the reliability in cover height design.

scholarly journals An Approach to Determine Optimal Bow Configuration of Polar Ships under Combined Ice and Calm-Water Conditions

2021 ◽  
Vol 9 (6) ◽  
pp. 680
Author(s):  
Hui Li ◽  
Yan Feng ◽  
Muk Chen Ong ◽  
Xin Zhao ◽  
Li Zhou
Keyword(s):  
Numerical Simulation ◽  
Water Resistance ◽  
Numerical Technique ◽  
Experimental Studies ◽  
Resistance Index ◽  
Simulation Method ◽  
Present Approach ◽  
Calm Water ◽  
Level Ice ◽  
Ice Resistance

Selecting an optimal bow configuration is critical to the preliminary design of polar ships. This paper proposes an approach to determine the optimal bow of polar ships based on present numerical simulation and available published experimental studies. Unlike conventional methods, the present approach integrates both ice resistance and calm-water resistance with the navigating time. A numerical simulation method of an icebreaking vessel going straight ahead in level ice is developed using SPH (smoothed particle hydrodynamics) numerical technique of LS-DYNA. The present numerical results for the ice resistance in level ice are in satisfactory agreement with the available published experimental data. The bow configurations with superior icebreaking capability are obtained by analyzing the sensitivities due to the buttock angle γ, the frame angle β and the waterline angle α. The calm-water resistance is calculated using FVM (finite volume method). Finally, an overall resistance index devised from the ship resistance in ice/water weighted by their corresponding weighted navigation time is proposed. The present approach can be used for evaluating the integrated resistance performance of the polar ships operating in both a water route and ice route.

A numerical simulation method for molten material behavior in nuclear reactors

2017 ◽  
Vol 322 ◽  
pp. 301-312 ◽  
Author(s):  
Susumu Yamashita ◽  
Takuya Ina ◽  
Yasuhiro Idomura ◽  
Hiroyuki Yoshida
Keyword(s):  
Numerical Simulation ◽  
Nuclear Reactors ◽  
Simulation Method ◽  
Material Behavior ◽  
Molten Material ◽  
Numerical Simulation Method

scholarly journals Strata behavior and control strategy of backfilling collaborate with caving fully-mechanized mining

2020 ◽  
Vol 12 (1) ◽  
pp. 703-717
Author(s):  
Yin Wei ◽  
Wang Jiaqi ◽  
Bai Xiaomin ◽  
Sun Wenjie ◽  
Zhou Zheyuan
Keyword(s):  
Numerical Simulation ◽  
Control Strategy ◽  
Three Dimensional ◽  
Simulation Method ◽  
Mine Pressure ◽  
Hydraulic Support ◽  
Transition Area ◽  
Pressure Concentration ◽  
Strata Behavior ◽  
And Control

AbstractThis article analyzes the technical difficulties in full-section backfill mining and briefly introduces the technical principle and advantages of backfilling combined with caving fully mechanized mining (BCCFM). To reveal the strata behavior law of the BCCFM workface, this work establishes a three-dimensional numerical model and designs a simulation method by dynamically updating the modulus parameter of the filling body. By the analysis of numerical simulation, the following conclusions about strata behavior of the BCCFM workface were drawn. (1) The strata behavior of the BCCFM workface shows significant nonsymmetrical characteristics, and the pressure in the caving section is higher than that in the backfilling section. φ has the greatest influence on the backfilling section and the least influence on the caving section. C has a significant influence on the range of abutment pressure in the backfilling section. (2) There exits the transition area with strong mine pressure of the BCCFM workface. φ and C have significant effect on the degree of pressure concentration but little effect on the influence range of strong mine pressure in the transition area. (3) Under different conditions, the influence range of strong mine pressure is all less than 6 m. This article puts forward a control strategy of mine pressure in the transition area, which is appropriately improving the strength of the transition hydraulic support within the influence range (6 m) in the transition area according to the pressure concentration coefficient. The field measurement value of Ji15-31010 workface was consistent with numerical simulation, which verifies the reliability of control strategy of the BCCFM workface.

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