Study on the explosion wave and crack field of an eccentric decoupled charge

2021 ◽  
Author(s):  
Jinjing Zuo ◽  
Renshu Yang ◽  
Min Gong ◽  
Peng Xu
Keyword(s):  
2012 ◽  
Vol 57 (3) ◽  
pp. 601-618 ◽  
Author(s):  
Vasyl Moisyshyn ◽  
Vasyl Yacyshyn ◽  
Oleg Vytyaz

Abstract Studied here are the results of the asymmetric problem solution of the thick walled circular cylinder elasticity using the spatial characteristics technique. The practical implementation of the solution of the problem is based on the calculation of the stress-caused deformation state of the stuck drilling string zone affected by the explosion wave action upon the inner wall of the pipe. Suggested here is the technique for determining axual σz and circular σθ stress on the drill pipe wall as well as the radial displacements ur of the stuck drill pipe outer surface under the action of the explosion shock wave. The above technique enables to make a sound selection of the cylindrical explosive charge weight in order to avoid the residual strain during the drilling string shaping off and uncoupling the threaded joints or to prevent them from exceeding the admissible level.


The measurement of the pressure produced in the “explosion-wave” in gaseous mixtures is difficult because of the rapidity of movement of the wave and the short time for which the pressure over any given area lasts. In 1894 Dixon and Cain pointed out that the pressures obtained by firing a mixture in a closed vessel did not correspond to pressures in the wave front. Following a suggestion of Mallard and Le Chatelier, they used a method in which glass tubes of known strength were fractured by the explosion-wave, it being assumed that “if a pressure is produced in a glass tube greater than it can stand, the glass will be broken although the pressure may only last for a very short interval of time.” The strength of the glass tubes was found by determining the static pressures required to break similar pieces. It was found that three lengths from the same piece of glass tubing required respectively 890, 950 and 1220 lbs. per square inch to fracture them: the accuracy of the results was therefore not very great. Dixon and Cain estimated that the pressure in the explosion-wave in C 2 N 2 + O 2 lay, probably, between 70 and 120 atmospheres and that in C 2 N 2 O + 2N 2 between 63 and 84 atmospheres. Jones and Bower cast some doubt on the pressures given by Dixon and Cain, and suggested that they were the pressures produced just after detonation had been re-established when the explosion-wave had been damped down at a junction. The pressure in the wave front of the fully established detonation wave in the mixture C 2 N 2 + O 2 was estimated by Jones and Bower to lie between 58 and 75 atmospheres.


The experiments described in this memoir were undertaken with two objects in the first place, to obtain information concerning the course of chemical change pursued by reacting gases; and, secondly, to examine the nature of the “explosion-wave” in gaseous mixtures discovered by M. Berthelot. The idea of using the rate of explosion as a means of determining the course of a chemical reaction occurred to me in 1877, when investigating the influence of steam on the union of carbonic oxide and oxygen. If steam acts as a carrier of oxygen to the carbonic oxide by a series of alternate reductions and oxidations, an increase in the amount of steam present, beyond that required to initiate the reaction, should be accompanied by an increase in the rate of combination up to a certain limit. Attempts were therefore made to detect such an increase by measuring the velocity of the flame in a tube. But while the difference in the rate of explosion between the nearly dry and the moist gases was well marked, the attempts to directly measure the rate of the explosion of the moist gases failed, owing to the great rapidity of the flame. In the spring of 1881 I attempted to measure the rate of explosion of carbonic oxide and oxygen with varying quantities of steam by photographing on a moving plate the flashes at the beginning and end of a closed tube 20 feet long. The two flashes appeared to be simultaneous to the eye, but no record of the rate was obtained, for the apparatus was broken to pieces by the violence of the explosion. Shortly after this attempt was made the first of the brilliant series of papers by MM. Berthelot and Vieille, and by MM. Mallard and Le Chateliek, was read before the French Academy of Sciences. The work of these French chemists has opened a new era in the theory of explosions.


1976 ◽  
Vol 12 (5) ◽  
pp. 718-720 ◽  
Author(s):  
R. G. Yakupov

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