RU2498200C1 - Contact-sector charge of sheet explosive - Google Patents

Abstract

FIELD: weapons and ammunition.

SUBSTANCE: contact-sector charge of a sheet explosive includes a detonator, an initiation system and an explosive charge. The latter is made in the form of sections with breakdown into sectors with a gap between them. Initiation system is made in the form of explosive strips of equal length and minimum width.

EFFECT: invention allows performing stable detonation at formation of non-interacting detonation waves at simultaneous multipoint discrete initiation.

2 dwg

Description

The invention relates to techniques for the explosion of areal charges with a small discontinuity of explosions, and in particular to the field of study of the behavior of structures under pulsed action on them, and can be used to create shock waves in determining the strength properties of promising materials.

A device for generating a blast wave, based on the application and detonation of a thin layer of blasting explosive (BB) on the surface of the test sample [1]. The explosive contact charge is placed in the form of a layer on the sample surface and is initiated on one side of the charge. The disadvantages of the device are: the non-simultaneous application of the load created by the sliding detonation of a thin explosive layer, the difficulty of implementing the creation of a plane-parallel shock wave and a low-pressure pressure pulse determined by the explosive thickness critical for detonation.

Contact blasting of sheet explosives is not suitable for characterizing materials that have low mechanical strength, therefore blasting is used through a damper or an equidistant surface charge carried to a given distance [1].

Also known is a device for initiating spatially-extended surfaces of explosive charges with low time difference [2]. In the device, an electric pulse is supplied to electric detonators mounted on a given surface of the detonated areal explosive charge. Detonators can be connected in series or in parallel to realize simultaneous multipoint initiation. The disadvantage of this device is the discrete nature of the detonation of sheet explosives by electric detonators, which leads to the initial perturbation of the detonation front and the appearance of the so-called “knife effect” on the surface of the material due to the interaction of detonation waves from different detonators. Detonation of electric detonators creates additional load and local impact on the loading surface.

The closest in technical essence and the achieved result to the proposed invention is a device for generating a blast wave [3] in which, for multipoint initiation, the chain of detonators is replaced by detonation wiring with branched end sections located on the main explosive charge or on an additional layer of flexible explosive acting as an intermediate charge. With the help of wiring, a multipoint initiation of the area charge is carried out, which allows you to set the required motion of the detonation wave, but does not exclude the interaction of detonation waves coming from different points of initiation and, therefore, the “knife effect” on the loading surface (destruction of the barrier at the point of collision of detonation waves). The device does not allow simultaneously loading the elements of prefabricated objects with various pressure pulses, which is most likely when using the device in the practice of testing the mechanical resistance of various structures.

The technical result of the invention is the formation of non-interacting detonation waves with simultaneous multi-current discrete initiation, for which sectors are formed on the loading surface in sections of a contact-sector charge from sheet explosives.

This technical result is achieved in that the charge is performed from a sheet explosive, broken up to eliminate the “knife effect” into small sectors with gaps between them, eliminating the interaction of detonation waves coming from different points of initiation and ensuring uniform loading and placed directly on the obstacle or on a layer of porous material (damper). The connection of the damper, explosives and barriers is carried out by gluing. Each sector of the charge is initiated at one point by an explosive strip with a width that is minimally possible for stable detonation (~ 5 mm), which virtually eliminates the local action of explosives at the points where the charge and strip are glued together. Strips of the same length are collected on one side into a beam and are initiated by a high-speed detonator (with a short response time). The detonator is separated from the loading surface and does not create additional load on the target. Multipoint initiation ensures the simultaneous application of influence due to the initiation of sections from strips of the same length connected in a bundle and connected with electric detonators.

When using multi-section loading of object structures, the contact charge is made in the form of interconnected groups of sectors connected to the explosive line through a detonation distributor. The number of sectors and their configuration is determined during the design of the charge, taking into account the best reproduction of the total pressure pulse. Sectors can be in the form of a square, an equilateral polyhedron, or are made in the form of cells with an initiation point in the geometric center of the figure. The sector initiation time is determined by the distance from the initiation center to the extreme point of the figure and the velocity of the detonation wave and is calculated when the charge is designed. By reducing the size of the sectors, it is possible, accordingly, to reduce the total detonation time of areal charges.

The implementation scheme of the proposed contact-sector charge is presented in figure 1, which shows: 1 - electric detonators; 2 - explosive charge sections, creating a mechanical load on the structure of the object; 3 - initiation system; 4 - gaps between sections.

The device operates as follows: the charge is placed on the barrier or on the damper of the structure, and the initiation system is made in the form of a beam of interconnecting groups of segments of explosives and connected with a blast line, detonation is excited in the sectors of the contact charge of the sheet explosives from the initiation system, and a detonation wave sliding along the loading surface is formed Thus, the synchronization of the generated detonation wave in the charge sectors is ensured. The simultaneous loading of the prefabricated structure of the object is ensured by the multipoint initiation of charge sections, while a multi-section charge can reproduce simultaneously loading of structural elements with various pressure pulses (Fig. 2).

Implementation of the developed device was carried out using the Institute's facilities and made it possible to obtain shock-wave loading of structures with a duration of 1-10 μs and a pressure pulse of 50-500 Pa · s, while 10 strips with a width of 2 mm from an elastic explosive were initiated from one detonator. The division of the area explosive charge into sections with a gap between them of 1 to 5 mm does not change the general character of the deformation of the target.

The proposed device for reproducing a mechanical pressure pulse makes it possible to evaluate the strength of samples of structural materials under conditions as close as possible to those required, while a detonation wave front that is smooth without disturbances is formed.

The developed device can be used to load not only flat structures, but also curved surfaces of prefabricated objects. The initiation of surface charges from explosive strips with one detonator requires less preparation costs compared to a system of multiple detonators. The loading of the whole structure with various pulses makes it possible to evaluate its deformation taking into account the joint nodes and rigid pinching of the ends of the structure, the interaction of shock waves in the prefabricated structure.

Information sources

1. Explosion Physics / Ed. Orlenko L.P. T.2, M. Fizmatlit, 2002. S.536-541.

2. Patent for invention No. 2156944 of August 2, 1999

3. Patent for the invention "Device for the formation of a blast wave" No. 21595935 dated August 5, 1997

Claims (1)

A contact sector charge from a sheet explosive containing a detonator, an initiation system, an explosive charge, characterized in that the charge is made in sections, each of which is divided into sectors with gaps between them, eliminating the interaction of detonation waves coming from different points of initiation , and ensuring uniform loading, while the initiation system is made in the form of strips of explosives of the same length and minimum width for stable detonation.

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