scholarly journals The research into the propagation law of the shock wave of a gas explosion inside a building

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Shu-Chao Lin ◽  
You-Chun Xu ◽  
Pei-Dong Yang ◽  
Shan Gao ◽  
Yi-Jun Zhou ◽  
...  
Keyword(s):  
Shock Wave ◽  
Peak Pressure ◽  
Initial Conditions ◽  
Three Dimensional ◽  
Time History ◽  
Element Model ◽  
Space Distribution ◽  
Gas Explosion ◽  
Propagation Law ◽  
Three Dimensional Finite Element

Based on the dissipation rate conservation equations of turbulent kinetic energy in the k-ε turbulence model, a complicated three-dimensional finite element model of a kitchen filled with gas mixture is developed by using the open source field operation and manipulation (OpenFOAM). Two representative kitchens were used to investigate the propagation law of the shock wave of a gas explosion inside a building by considering the key characteristics of the blast shock wave. The influence of some crucial parameters, such as initial conditions and kitchen parameters, on the properties of the blast shock wave is investigated. The basic steps to predict the peak pressure of the blast shock wave are given in consideration of the initial condition and the kitchen whilst the injury effect of the blast shock wave on the humans and animals is evaluated. The research results indicate that the pressure time history and the peak pressure space distribution are greatly influenced by the kitchen design layout. The coupled interaction between the initial temperature and gas volume concentration, especially at the upper and lower explosion limits of the gas, significantly affects the peak pressure. The peak pressure varies significantly with the opening and the buffer; however, it has little relation with the width, length, and height of the kitchen. The proposed method can accurately and effectively predict the peak pressure of the blast shock wave inside buildings. In terms of the peak pressure space distribution of the explosion shock wave, the peak pressure is much higher than the threshold of the killing pressure, which is unsafe for the humans and animals in the building.

scholarly journals The Study on the Shock Wave Propagation Rule of a Gas Explosion in a Gas Compartment

2022 ◽  
Vol 2022 ◽  
pp. 1-17
Author(s):  
Shu-Chao Lin ◽  
Qing-Zhao Hou ◽  
Anna Derlatka ◽  
Shan Gao ◽  
Jin-Jun Kang ◽  
...  
Keyword(s):  
Shock Wave ◽  
Wave Propagation ◽  
Blast Wave ◽  
Peak Pressure ◽  
Initial Conditions ◽  
Element Model ◽  
Shock Wave Propagation ◽  
Gas Explosion ◽  
Pressure Threshold ◽  
Propagation Rule

Combined with the k-ε turbulence model of general application, a refined finite element model of a utility tunnel’s gas compartment filled with the methane/air mixture is developed. A series of analyses are made by using the powerful industry-leading computational fluid dynamics (CFD) software flame acceleration simulator (FLACS) to study the shock wave propagation rule in the gas compartment. The longitudinal and transversal distribution laws of the explosion shock wave are gained taking into consideration the spatial characteristics of the gas compartment. The influences of a few parameters, such as initial conditions and section size of the gas compartment, on the shock wave propagation rule are further discussed. The basic procedure for predicting the peak pressure of the blast wave is provided by considering the initial conditions and the gas compartment, and the corresponding injury effect of the explosion wave on the living beings is assessed. The investigation demonstrates that the peak pressure by the coupled effect between the initial conditions is significantly influenced, especially at the upper and lower gas explosion limits. The peak pressure increases gradually as the width or height increases, and both basically meet the linear relation. The proposed method can forecast the peak pressure of the explosion shock wave in the gas compartment accurately. According to the peak pressure longitudinal and transversal distributions of the blast wave, the peak pressure is far greater than the killing pressure threshold in the underground and closed space; consequently, it is not safe for the living beings in the gas compartment.

Study on Seismic Safety Evaluation of RCC Gravity Dam Based on Strength

2014 ◽  
Vol 501-504 ◽  
pp. 1493-1497
Author(s):  
Shu He Wang ◽  
Ji Yuan ◽  
Rui Guo Ma ◽  
Ju Bing Zhang
Keyword(s):  
Finite Element ◽  
Response Spectrum ◽  
Three Dimensional ◽  
Safety Evaluation ◽  
Time History ◽  
Element Model ◽  
Gravity Dam ◽  
Seismic Safety ◽  
Finite Element Software ◽  
Three Dimensional Finite Element

According to No.3 dam section of Dahuaqiao gravity dam, a three-dimensional finite element model is built by finite element software ANSYS. Mechanics of materials method, response spectrum method and time history analysis method are employed to analyze the strength of the dam section. Results show that the stress of dam toe, dam heel and downstream fold slope are relatively high and stress concentration emerges in those positions. The phenomenon indicates that these areas are vulnerable under the earthquake and precautions must be taken. But under the designed earthquake, the maximum stress of the dam section is below the allowable stress, representing the dam is in a safe state and the strength requirement is satisfied.

Modal Analysis and Seismic Response Evaluation on Structures of Advanced PWR

2013 ◽  
Vol 838-841 ◽  
pp. 1471-1475
Author(s):  
Guo Liang Zhou ◽  
Hui Tang
Keyword(s):  
Modal Analysis ◽  
Response Spectrum ◽  
Three Dimensional ◽  
Time History ◽  
Element Model ◽  
Structural Dynamic ◽  
Dimensional Finite Element ◽  
Nuclear Structures ◽  
Three Dimensional Finite Element ◽  
New Generation

To evaluate the earthquake resistant behavior of the nuclear island buildings of new generation PWR, in this study we formed the three dimensional finite element model of nuclear island structures ,which incluse shield building, the auxiliary building, the containment vessel, and the containment internal structures. Modal analysis was performed to to reveal the structural dynamic characteristics.And with the auumption of hard bedrock support media ,the dynamic response nanalysis of the nuclear structures under earthquake was conducted,respectively with response spectrum method and time history method.It shows that the seimic response of the strucures conform with the design level.Under the input excitations of SSE(safe shutdown earthquake) level, the iner forces and deforamtions can be well controlled in linear elasticity.

Dynamic Time History Analysis on Groundwater Hydraulic Tunnel under Three Dimensional Viscoelastic Boundary Conditions

2013 ◽  
Vol 302 ◽  
pp. 622-627
Author(s):  
Ji Yao ◽  
Liang Cao ◽  
Hui Min Wang ◽  
Li Jie Zhang ◽  
Liang Wu ◽  
...  
Keyword(s):  
Boundary Conditions ◽  
Seismic Response ◽  
Seismic Waves ◽  
Three Dimensional ◽  
Time History ◽  
Element Model ◽  
Rigid Boundary ◽  
Dimensional Finite Element ◽  
Dynamic Time ◽  
Three Dimensional Finite Element

The three dimensional finite element model of a groundwater hydraulic tunnel was eatablished in this paper by FEM software ANSYS, two seismic waves of bedrock wave and EI-centro wave in similar sites were entered, and dynamic time history method was applied to compare the seismic response of the two hydraulic tunnels which were under rigid boundary conditions and viscoelastic boundary conditions respectively. The results showed that, the dynamic response of the model under rigid boundary conditions was larger than the response under viscoelastic boundary, and the viscoelastic boundary was closer to the actual situation. Under viscoelastic boundary conditions, the smaller depth of the hydraulic tunnel, the more intensive of the seismic response.

Finite Element Analysis of Nonuniformity of Tires with Imperfections5

2007 ◽  
Vol 35 (3) ◽  
pp. 226-238 ◽  
Author(s):  
K. M. Jeong ◽  
K. W. Kim ◽  
H. G. Beom ◽  
J. U. Park
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Radial Force ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Dimensional Finite Element ◽  
Force Variation ◽  
Three Dimensional Finite Element

Abstract The effects of variations in stiffness and geometry on the nonuniformity of tires are investigated by using the finite element analysis. In order to evaluate tire uniformity, a three-dimensional finite element model of the tire with imperfections is developed. This paper considers how imperfections, such as variations in stiffness or geometry and run-out, contribute to detrimental effects on tire nonuniformity. It is found that the radial force variation of a tire with imperfections depends strongly on the geometrical variations of the tire.

Study of dynamic pressure on the packer for deep-water perforation

Open Physics ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. 215-223
Author(s):  
Hao Huang ◽  
Qiao Deng ◽  
Hui Zhang
Keyword(s):  
Deep Water ◽  
Peak Pressure ◽  
Orthogonal Design ◽  
Dynamic Pressure ◽  
Three Dimensional ◽  
Calculation Model ◽  
Well Testing ◽  
Technical Problems ◽  
Wellbore Pressure ◽  
Three Dimensional Finite Element

Abstract The packer is one of the most important tools in deep-water perforation combined well testing, and its safety directly determines the success of perforation test operations. The study of dynamic perforating pressure on the packer is one of the key technical problems in the production of deep-water wells. However, there are few studies on the safety of packers with shock loads. In this article, the three-dimensional finite element models of downhole perforation have been established, and a series of numerical simulations are carried out by using orthogonal design. The relationship between the perforating peak pressure on the packer with the factors such as perforating charge quantity, wellbore pressure, perforating explosion volume, formation pressure, and elastic modulus is established. Meanwhile, the database is established based on the results of numerical simulation, and the calculation model of peak pressure on the packer during perforating is obtained by considering the reflection and transmission of shock waves on the packer. The results of this study have been applied in the field case of deep-water well, and the safety optimization program for deep-water downhole perforation safety has been put forward. This study provides important theoretical guidance for the safety of the packer during deep-water perforating.

scholarly journals Internal Force on and Deformation of Steel Assembled Supporting Structure of Foundation Pit under Thermal Stress

2021 ◽  
Vol 11 (5) ◽  
pp. 2225
Author(s):  
Fu Wang ◽  
Guijun Shi ◽  
Wenbo Zhai ◽  
Bin Li ◽  
Chao Zhang ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Bending Moment ◽  
High Strength ◽  
Element Model ◽  
Internal Force ◽  
Foundation Pit ◽  
Dimensional Finite Element ◽  
Influence Of Temperature On ◽  
Scale Experiment ◽  
Three Dimensional Finite Element

The steel assembled support structure of a foundation pit can be assembled easily with high strength and recycling value. Steel’s performance is significantly affected by the surrounding temperature due to its temperature sensitivity. Here, a full-scale experiment was conducted to study the influence of temperature on the internal force and deformation of supporting structures, and a three-dimensional finite element model was established for comparative analysis. The test results showed that under the temperature effect, the deformation of the central retaining pile was composed of rigid rotation and flexural deformation, while the adjacent pile of central retaining pile only experienced flexural deformation. The stress on the retaining pile crown changed little, while more stress accumulated at the bottom. Compared with the crown beam and waist beam 2, the stress on waist beam 1 was significantly affected by the temperature and increased by about 0.70 MPa/°C. Meanwhile, the stress of the rigid panel was greatly affected by the temperature, increasing 78% and 82% when the temperature increased by 15 °C on rigid panel 1 and rigid panel 2, respectively. The comparative simulation results indicated that the bending moment and shear strength of pile 1 were markedly affected by the temperature, but pile 2 and pile 3 were basically stable. Lastly, as the temperature varied, waist beam 2 had the largest change in the deflection, followed by waist beam 1; the crown beam experienced the smallest change in the deflection.

Process Modeling in Laser Deposition of Multilayer SS410 Steel

2007 ◽  
Vol 129 (6) ◽  
pp. 1028-1034 ◽  
Author(s):  
Liang Wang ◽  
Sergio Felicelli
Keyword(s):  
Phase Transformation ◽  
Temperature Distribution ◽  
Three Dimensional ◽  
Element Model ◽  
Traverse Speed ◽  
Processing Parameters ◽  
Dimensional Finite Element ◽  
Net Shaping ◽  
Three Dimensional Finite Element ◽  
Continuous Cooling Transformation Diagram

A three-dimensional finite element model was developed to predict the temperature distribution and phase transformation in deposited stainless steel 410 (SS410) during the Laser Engineered Net Shaping (LENS™) rapid fabrication process. The development of the model was carried out using the SYSWELD software package. The model calculates the evolution of temperature in the part during the fabrication of a SS410 plate. The metallurgical transformations are taken into account using the temperature-dependent material properties and the continuous cooling transformation diagram. The ferritic and martensitic transformation as well as austenitization and tempering of martensite are considered. The influence of processing parameters such as laser power and traverse speed on the phase transformation and the consequent hardness are analyzed. The potential presence of porosity due to lack of fusion is also discussed. The results show that the temperature distribution, the microstructure, and hardness in the final part depend significantly on the processing parameters.

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