Effect of explosion source location on tunnel damage

2020 ◽  
Vol 11 (4) ◽  
pp. 448-467
Author(s):  
Petr Prochazka ◽  
Dagmar Jandeková
Keyword(s):  
Shock Wave ◽  
Experimental Study ◽  
Shock Waves ◽  
Longitudinal Axis ◽  
Source Location ◽  
Tunnel Lining ◽  
Scale Models

The experimental study, the results of which are presented in this article, focuses on the shock wave behavior in scale models of tunnel structures and their consequences on the damage of tubes simulating tunnel lining. The source of the explosion is located either on the longitudinal axis of the tunnel or it is located near the bottom of the tunnel. The second case is more akin to reality. This article analyzes the consequences of the location of explosion sources and the influence of their brisance. In order to compare the effects of explosions on the tunnel lining, the effect of the charge deposited on the axis of the tunnel is investigated on a 0.5-m-diameter tube, while the effect of the charge deposited outside the tunnel axis is monitored on a 1-m-diameter tube. Thus, the magnitudes of the brisance may be comparable for both cases. The characteristics of the shock waves are described. The mass of the charges is graded so as not to allow a total collapse of the structure, but to manifest its damage.

Research on Propagation Numerical Simulation of Blast Shock Waves in Subway Station

2013 ◽  
Vol 380-384 ◽  
pp. 1725-1728
Author(s):  
Yang Hu ◽  
Huai Yu Kang
Keyword(s):  
Numerical Simulation ◽  
Shock Wave ◽  
Experimental Study ◽  
Shock Waves ◽  
Theoretical Basis ◽  
Damage Effect ◽  
Subway Station ◽  
Element Calculation ◽  
Dynamic Finite Element ◽  
Walking Pattern

In this paper, we Research on Propagation Numerical Simulation and damage effect of Blast Shock Waves in Subway Station by using LS-DYNA dynamic finite element calculation program , the results reproduce the formation process of the explosive flow field, and analysis the shock wave waveform, attenuation and walking pattern, provides the theoretical basis for further experimental study.

The perturbed region behind a diffracting shock wave

1967 ◽  
Vol 29 (4) ◽  
pp. 705-719 ◽  
Author(s):  
B. W. Skews
Keyword(s):  
Shock Wave ◽  
Experimental Study ◽  
Mach Number ◽  
Shock Waves ◽  
Contact Surface ◽  
Fair Agreement ◽  
Number Range ◽  
Corner Angle ◽  
Theoretical Predictions

The results of an experimental study of the diffraction of shock waves on plane-walled convex corners are given for a Mach number range from 1·0 to 5·0. The behaviour of the disturbances produced in the region perturbed by the corner are discussed. It is shown that the position of the slipstream and tail of the Prandtl-Meyer fan, and the velocities of the contact surface and second shock become independent of corner angle for angles greater than 75°. Comparisons with theoretical predictions of Jones, Martin & Thornhill (1951) and Parks (1952) are included. In most cases fair agreement is obtained.

Investigation of shock-wave deformation history from recovered structure

1986 ◽  
Vol 44 ◽  
pp. 434-435
Author(s):  
M.A. Mogilevsky ◽  
L.S. Bushnev
Keyword(s):  
Shock Wave ◽  
Plastic Deformation ◽  
Dislocation Density ◽  
Shock Waves ◽  
Shock Front ◽  
Single Crystals ◽  
Residual Deformation ◽  
Deformation Structure ◽  
Deformation History ◽  
Deformation Velocity

Single crystals of Al were loaded by 15 to 40 GPa shock waves at 77 K with a pulse duration of 1.0 to 0.5 μs and a residual deformation of ∼1%. The analysis of deformation structure peculiarities allows the deformation history to be re-established.After a 20 to 40 GPa loading the dislocation density in the recovered samples was about 1010 cm-2. By measuring the thickness of the 40 GPa shock front in Al, a plastic deformation velocity of 1.07 x 108 s-1 is obtained, from where the moving dislocation density at the front is 7 x 1010 cm-2. A very small part of dislocations moves during the whole time of compression, i.e. a total dislocation density at the front must be in excess of this value by one or two orders. Consequently, due to extremely high stresses, at the front there exists a very unstable structure which is rearranged later with a noticeable decrease in dislocation density.

EXPERIMENTAL STUDY OF REACTION OF ETHANOL WITH OXYGEN BEHIND SHOCK WAVES USING ATOMIC RESONANCE ABSORPTION SPECTROSCOPY METHOD

2020 ◽  
Author(s):  
N. S. Bystrov ◽  
◽  
A. V. Emelianov ◽  
A. V. Eremin ◽  
P. I. Yatsenko ◽  
...  
Keyword(s):  
Experimental Study ◽  
Shock Waves ◽  
Absorption Spectroscopy ◽  
Vacuum Ultraviolet ◽  
Resonance Absorption ◽  
Atomic Resonance ◽  
Quantitative Measurements ◽  
Series Of Experiments ◽  
Kinetics Of Reaction ◽  
Oxygen Atoms

The kinetics of reaction of C2H5OH with N2O behind shock waves is studied. The quantitative measurements of the time profiles of concentration of O atoms were carried out by the method of atomic resonance absorption spectroscopy (ARAS) using resonance vacuum-ultraviolet line of O-atom at 130.5 nm. For the calibration of absorption intensity of oxygen atoms depending on its concentration, the special series of experiments in the mixture containing different amounts of N2O in Ar was carried out at T = 2100 ± 50 K when molecule of N2O is completely dissociated. An experimental study of the appearance and consumption of oxygen atoms during the reaction of ethanol with oxygen in mixture 10 ppm N2O + (10 ... 0.1) ppm C2H5OH + Ar at temperatures of 16002300 K and pressures of 200-300 kPa have been carried out. A kinetic analysis of obtained data was performed using the Chemkin package.

Features of spatial shock-wave flows in vapor-gas-liquid mixtures

2014 ◽  
Vol 10 ◽  
pp. 27-31
Author(s):  
R.Kh. Bolotnova ◽  
U.O. Agisheva ◽  
V.A. Buzina
Keyword(s):  
Shock Wave ◽  
High Pressure ◽  
Shock Waves ◽  
Liquid Mixture ◽  
Liquid Mixtures ◽  
Pressure Vessels ◽  
Water Mixture ◽  
Two Dimensional ◽  
Nonstationary Processes ◽  
Two Phase

The two-phase model of vapor-gas-liquid medium in axisymmetric two-dimensional formulation, taking into account vaporization is constructed. The nonstationary processes of boiling vapor-water mixture outflow from high-pressure vessels as a result of depressurization are studied. The problems of shock waves action on filled by gas-liquid mixture volumes are solved.

scholarly journals Nematic Dispersive Shock Waves from Nonlocal to Local

2021 ◽  
Vol 11 (11) ◽  
pp. 4736
Author(s):  
Saleh Baqer ◽  
Dimitrios J. Frantzeskakis ◽  
Theodoros P. Horikis ◽  
Côme Houdeville ◽  
Timothy R. Marchant ◽  
...  
Keyword(s):  
Shock Wave ◽  
Liquid Crystals ◽  
Shock Waves ◽  
Numerical Solutions ◽  
Wave Structure ◽  
Beam Power ◽  
Input Beam ◽  
Shock Wave Structure ◽  
Wave Solutions ◽  
Modulation Theory

The structure of optical dispersive shock waves in nematic liquid crystals is investigated as the power of the optical beam is varied, with six regimes identified, which complements previous work pertinent to low power beams only. It is found that the dispersive shock wave structure depends critically on the input beam power. In addition, it is known that nematic dispersive shock waves are resonant and the structure of this resonance is also critically dependent on the beam power. Whitham modulation theory is used to find solutions for the six regimes with the existence intervals for each identified. These dispersive shock wave solutions are compared with full numerical solutions of the nematic equations, and excellent agreement is found.

Experimental study of heat transfer in the boundary layer of a flat plate with the impact of weak shock waves on the leading edge

2020 ◽  
Author(s):  
V. L. Kocharin ◽  
A. A. Yatskikh ◽  
D. S. Prishchepova ◽  
A. V. Panina ◽  
Yu. G. Yermolaev ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Experimental Study ◽  
Shock Waves ◽  
Flat Plate ◽  
Leading Edge ◽  
Weak Shock ◽  
The Impact
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