Solution of Gas Explosion Load and Simulation of Dynamic Response of Multilayer Structures

2012 ◽  
Vol 557-559 ◽  
pp. 2401-2405
Author(s):  
Hua Dong Liu ◽  
Wei Qiang Wang
Keyword(s):  
Dynamic Response ◽  
Multilayer Structure ◽  
Radial Direction ◽  
Burst Pressure ◽  
Multilayer Structures ◽  
Gas Explosion ◽  
Explosion Pressure ◽  
Structure Strength ◽  
Explosion Load ◽  
Chemical Explosion

Chemical explosion may occur in urea reactor. The explosion load and the dynamic response of the multilayer structure are analyzed. Based on Russel model, the maximum explosion loads were calculated by thermodynamic methods. Dynamic response was simulated by Ls-dyna software. The result shows that the explosion pressure is smaller than the burst pressure; the stress distribution along the radial direction and the effective stress history are obtained and they both show some new features. The results may offer some reference significance for similar structure strength design and safe protection.

scholarly journals A Novel Design of Rescue Capsule considering the Pressure Characteristics and Thermal Dynamic Response with Thermomechanical Coupling Action Subjected to Gas Explosion Load

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Xiaowei Zhai ◽  
Shibo Wu ◽  
Kai Wang ◽  
Xiaokun Chen ◽  
Haitao Li
Keyword(s):  
Dynamic Response ◽  
Coal Mine ◽  
Coupling Effect ◽  
Design Method ◽  
Thermomechanical Coupling ◽  
Structural Safety ◽  
Coupling Mechanism ◽  
Gas Explosion ◽  
Explosion Load ◽  
Mine Rescue

To ensure the structural safety and reliability of coal mine rescue capsule in disastrous surroundings after gas explosion, in this paper, the thermomechanical coupling effect on a certain structure subjected to gas explosion was analyzed, and then a novel rescue capsule with a combination of radius and square features was designed according to the underground surroundings and relevant regulations on mine rescue devices. Foremost, the coupling mechanism of thermal-fluid-solid interaction between gas explosion shock wave and rescue capsule and the thermal dynamic response of the capsule subjected to explosion load of gas/air mixture was investigated and revealed by employing LS-DYNA. The variation laws and characteristics of stress field, displacement field, and temperature field of the capsule were analyzed based on the simulation results. Results show that the structural safety, tightness, and reliability of the capsule meet the requirements of the national safety regulations. The design method presented in this work provides a new thought for design of coal mine rescue capsule.

scholarly journals Self- and Dopant Diffusion in Extrinsic Boron Doped Isotopically Controlled Silicon Multilayer Structures

2002 ◽  
Vol 719 ◽  
Author(s):  
Ian D. Sharp ◽  
Hartmut A. Bracht ◽  
Hughes H. Silvestri ◽  
Samuel P. Nicols ◽  
Jeffrey W. Beeman ◽  
...  
Keyword(s):  
Multilayer Structure ◽  
Secondary Ion Mass Spectrometry ◽  
Diffusion Processes ◽  
Quantitative Description ◽  
Multilayer Structures ◽  
Dopant Diffusion ◽  
Enhanced Diffusion ◽  
Self Diffusion ◽  
Boron Doped ◽  
P Type

AbstractIsotopically controlled silicon multilayer structures were used to measure the enhancement of self- and dopant diffusion in extrinsic boron doped silicon. 30Si was used as a tracer through a multilayer structure of alternating natural Si and enriched 28Si layers. Low energy, high resolution secondary ion mass spectrometry (SIMS) allowed for simultaneous measurement of self- and dopant diffusion profiles of samples annealed at temperatures between 850°C and 1100°C. A specially designed ion-implanted amorphous Si surface layer was used as a dopant source to suppress excess defects in the multilayer structure, thereby eliminating transient enhanced diffusion (TED) behavior. Self- and dopant diffusion coefficients, diffusion mechanisms, and native defect charge states were determined from computer-aided modeling, based on differential equations describing the diffusion processes. We present a quantitative description of B diffusion enhanced self-diffusion in silicon and conclude that the diffusion of both B and Si is mainly mediated by neutral and singly positively charged self-interstitials under p-type doping. No significant contribution of vacancies to either B or Si diffusion is observed.

Study on the Effects of the Nonhomogeneous Material Properties on the Structure Strength of the Induction Quenched Crankshaft

2014 ◽  
Vol 703 ◽  
pp. 400-405
Author(s):  
Ji Shan Li ◽  
Ri Dong Liao ◽  
Guo Hua Chen
Keyword(s):  
Elastic Modulus ◽  
Material Properties ◽  
Fem Model ◽  
Explosion Pressure ◽  
Nonhomogeneous Material ◽  
Linear Rule ◽  
Distribution Rule ◽  
The Matrix ◽  
Nonhomogeneous Properties ◽  
Structure Strength

To study the effects of the nonhomogeneous material properties on the stress in an induction quenched crankshaft, the FEM model considering the nonhomogeneous material properties was established to simulate the stress in the crankshaft under the explosion pressure. Results showed that the nonhomogeneous properties almost didn’t vary the Mises stress distribution rule in the crankshaft. The maximum Mises stress, the ratio of the elastic modulus of the surface layer and the matrix followed a linear rule nearly. Moreover, the maximum Mises stress increased with the ratio. Besides, effect of elastic modulus distribution in the transition layer on the maximum stress could be ignored. To simplify the establishment of the FEM model, the elastic modulus could be set to either equal to the surface layer’s or the matrix’s.

Study on Numerical Simulation of Gas Explosion inside Compression Compartment of Gas Filling Station

2014 ◽  
Vol 962-965 ◽  
pp. 531-538 ◽  
Author(s):  
Yu Wang ◽  
Yun Yi Wu
Keyword(s):  
Numerical Simulation ◽  
Influence Factors ◽  
Unit Weight ◽  
Point Location ◽  
Gas Explosion ◽  
Ignition Point ◽  
Explosion Pressure ◽  
Propagation Behavior ◽  
Filling Station ◽  
Open Pressure

For the compression compartment safety design in gas filling station, hazards of gas explosion inside compression compartment should be assessed, and explosion energy as well as influence factors should be determined. In this paper, numerical simulation was adopted to build 3D model of compression compartment and simulate gas explosion pressure and flame propagation behavior under different ignition point location, open-pressure and weight of relief panels. The results show that the ignition point location relative to the location of the vent opening and relief panel’s characteristics is very important for gas explosion inside compression compartment. The nearer the ignition point location is away from the venting opening location, the smaller the caused explosion pressure will be. For the relief panel, explosion pressure is proportional with the open-pressure and the weight of relief panel. Besides the rational distribution of ignition source and the adoption of relief panel with less unit weight and relief pressure, the crushing material damage and secondary hazard of flame should also be noticed in order to mitigate the hazard of gas explosion.

Optical Modulation Spectroscopy of a-Si:H Based Multilayer Structures

1986 ◽  
Vol 77 ◽  
Author(s):  
T. X. Zhou ◽  
H. Stoddart ◽  
Z. Vardeny ◽  
J. Tauc ◽  
B. Abeles
Keyword(s):  
Steady State ◽  
Temperature Dependence ◽  
Multilayer Structure ◽  
Optical Modulation ◽  
Multilayer Structures ◽  
Time Decay ◽  
Dangling Bonds ◽  
Band Tail ◽  
Modulation Spectroscopy ◽  
Modulation Spectrum

ABSTRACTSteady state optical modulation spectrum of a-Si:H/a-SiNx:H multilayer structure, its temperature dependence and time decay have been studied. For multilayers with very thin sublayers the onset of the spectrum is more gradual and occurs at higher energy than the spectrum for unlayered a-Si:H, indicating a broadening of the band tail. For larger layer thicknesses the optical modulation spectrum is compared to that for P-doped a-Si:H and interpreted as due to charged dangling bonds at the interfaces.

scholarly journals Non-equilibrium critical dynamics of low-dimensional magnetics and multilayer structures

2018 ◽  
Vol 185 ◽  
pp. 11009
Author(s):  
Pavel V. Prudnikov ◽  
Vladimir V. Prudnikov ◽  
Alena Yu. Danilova ◽  
Vadim O. Borzilov ◽  
Georgy G. Baksheev
Keyword(s):  
Critical Behavior ◽  
Multilayer Structure ◽  
Heisenberg Model ◽  
Uniaxial Anisotropy ◽  
Multilayer Structures ◽  
Critical Dynamics ◽  
Aging Effects ◽  
Magnetic Systems ◽  
Low Dimensional ◽  
Non Equilibrium

The Monte Carlo simulation of the critical behavior of multilayer structures based on anisotropic Heisenberg model is performed. The influence of the uniaxial anisotropy on the critical behavior of the thin Heisenberg-like film is described. The investigation of non-equilibrium critical behavior of multilayer structure which correspond to the nanoscale superlattice Co/Cu demonstrates that the aging effects can be observed in a wider temperature range than for bulk magnetic systems.

LOCAL DOPING AND OPTIMAL ANNEALING OF A MESH MULTILAYER STRUCTURE TO DECREASE THE SPATIAL DIMENSIONS OF INTEGRATED p–n-JUNCTIONS

NANO ◽  
2009 ◽  
Vol 04 (05) ◽  
pp. 303-323 ◽  
Author(s):  
E. L. PANKRATOV
Keyword(s):  
Integrated Circuits ◽  
Annealing Time ◽  
Multilayer Structure ◽  
Paper Analysis ◽  
Bipolar Transistor ◽  
Multilayer Structures ◽  
Dopant Distribution ◽  
Spatial Dimensions ◽  
Dopant Redistribution ◽  
Junction Rectifiers

It has been recently shown that inhomogeneity of a multilayer structure and optimization of annealing time give us the possibility to decrease the depth of p–n-junctions, which were produced in the structures. The additional to the considered effect is increasing of homogeneity of dopant distribution in enriched by the dopant area of p–n-junction. In the present paper analysis of dopant redistribution in a multilayer structures during production a series of p–n-junctions, which was produced in the multilayer structures, has been done. We consider an approach to increase the sharpness of both diffused-junction and implanted-junction rectifiers, which comprise in a bipolar transistor or thyristor, and increasing of homogeneity of dopants distributions in enriched by the dopants areas of p–n-junctions. The approach gives us possibility to increase the degree of integration of p–n-junctions, which was produced as elements of integrated circuits. Optimization of annealing time for simultaneously increasing of the sharpness and homogeneity has been done.

On approach to model stabilization of anomalous distribution of concentration of radiation defects in a multilayer structure

2018 ◽  
Vol 14 (5) ◽  
pp. 984-998
Author(s):  
Evgeny L. Pankratov
Keyword(s):  
Multilayer Structure ◽  
Design Methodology ◽  
Multilayer Structures ◽  
Radiation Defects ◽  
Boundary Problems ◽  
Content Type

Purpose The purpose of this paper is to introduce a model of redistribution of point radiation defects, interaction between themselves and redistribution of their simplest complexes in a multilayer structure. The model gives a possibility to qualitatively describe nonmonotonicity of distributions of concentrations of radiation defects on interfaces between layers of the structure, which recently was found experimentally. To take into account the nonmonotonicity, the authors complement the model for the analysis of distribution of concentration of radiation defects, which were recently used in the literature. To analyze the model, the authors used an approach of solution of boundary problems, which could be used without crosslinking of solutions on interfaces between layers of the considered multilayer structures. Design/methodology/approach The authors introduce a model of redistribution of point radiation defects, interaction between themselves and redistribution of their simplest complexes in a multilayer structure. The model gives a possibility to qualitatively describe nonmonotonicity of distributions of concentrations of radiation defects on interfaces between layers of the structure, which recently was found experimentally. To take into account the nonmonotonicity, the authors complement the model for analysis of distribution of concentration of radiation defects, which were recently used in the literature. To analyze the model, the authors used an approach of solution of boundary problems, which could be used without crosslinking of solutions on interfaces between layers of the considered multilayer structures. Findings The authors obtain better agreement of obtain results in comparison with recently obtained results in the literature. Originality/value The results are original.

Thermal Characterization of Cu∕CoFe Multilayer for Giant Magnetoresistive Head Applications

2005 ◽  
Vol 128 (2) ◽  
pp. 113-120 ◽  
Author(s):  
Y. Yang ◽  
R. M. White ◽  
M. Asheghi
Keyword(s):  
Electrical Resistance ◽  
Multilayer Structure ◽  
Giant Magnetoresistance ◽  
Room Temperature ◽  
Thermal Characterization ◽  
Disk Drive ◽  
Multilayer Structures ◽  
Large Decrease ◽  
Resistance Thermometry

Giant magnetoresistance (GMR) head technology is one of the latest advancements in the hard disk drive (HDD) storage industry. The GMR head multilayer structure consists of alternating layers of extremely thin metallic ferromagnetic and nonmagnetic films. A large decrease in the electrical resistivity from antiparallel to parallel alignment of the film magnetizations is observed, known as the GMR effect. The present work characterizes the in-plane electrical and thermal conductivities of Cu∕CoFe GMR multilayer structures in the temperature range of 50K to 340K using Joule-heating and electrical resistance thermometry on suspended bridges. The thermal conductivity of the GMR layer monotonically increases from 25Wm−1K−1 (at 55K) to nearly 50Wm−1K−1 (at room temperature). We also report a GMR ratio of 17% and a large magnetothermal resistance effect (GMTR) of 25% in the Cu∕CoFe multilayer structure.

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