LU500059B1 - Safe Separation Method of Plates and Charging Constitution - Google Patents

Abstract

The invention relates to a safe separation method of plates and a charging constitution, which can reduce main control parameters in the separation process of plates by theoretical derivation. The invention specifically includes plates, explosives, detonators, buffer layers, spacer layers and grooves. It is characterized in that a circular hole is opened at the center of the plates and grooves are notched on both sides of the central axis of the plates. A buffer layer is placed in the circular hole with explosives placed inside. Between the explosives, there is a spacer layer, composed of nonel tubes covered by plastic sleeves. The explosives are detonated by the detonator. According to the invention, plates can be separated safely without redundant power. Meanwhile, relying on reliable theoretical derivation, the experimental process is simple and only a few experiments are required.

Description

DESCRIPTION Safe Separation Method of Plates and Charging Constitution

TECHNICAL FIELD The invention involves the field of explosive working, and particularly relates to a safe separation method of plates and a charging constitution.

BACKGROUND Accidents caused by the non-containment of aero engines can lead to serious air crashes with aircraft crash and human deaths. Besides, high-speed and high-energy dangerous debris flying through the casing will damage the aircraft cabin, fuel tank, hydraulic pipeline and electrical control circuit, which seriously endangers flight safety. Therefore, it is of great significance to study the containment of aero engine casing. Casing containment test aims to verify the containment ability of blades flying out after casing is broken in half. When casing containment test is carried out, blades are required to break at specific positions and rotating speeds without excessive residual velocity and fragment sprayed. It is decided to use explosive method to separate the blades without giving redundant power to the blades, which provides further ideas for the casing containment test.

SUMMARY The purpose of the invention is to provide a safe separation method of plates and a charging constitution, which can reduce the main control parameters in the plate separation process by theoretical derivation, simplify the experimental process and decrease the number of experiments. Moreover, the plates can be safely separated without redundant power. The proposed method can be used as an operation method to safely separate plates by explosion, which provides a theoretical basis for further optimization of such explosive separation structure as well as further ideas for casing containment test.

According to the technical scheme adopted by the invention, the safe separation method of plates and the charging constitution specifically comprise plates, explosives, detonators, air-spaced layers, buffer layers, plastic sleeves and grooves.

Wherein, a circular hole is opened at the center of the plates and grooves are notched on both sides of the central axis of the plates.

A buffer layer is placed in the circular hole with explosives placed inside.

Specifically, the explosive is a decoupled charging constitution with the explosive diameter smaller than the blasthole diameter.

The interval charging constitution is arranged between the explosive and the blasthole wall.

The explosive is in an interval charging constitution, that is, there are interval charging constitutions between the explosives.

Further, a spacer layer is arranged between the explosives, which is composed of nonel tubes covered by plastic sleeves.

The explosives are detonated by the detonator.

Preferably, the safe separation method of plates and the charging constitution provided by the invention reduce the main control parameters in the plate separation process by theoretical derivation, simplify the experimental process and reduce the number of experiments.

The theoretical derivation is described as follows.

The main control parameters of plates’ fracture during explosion include explosive parameters, plate parameters and buffer layer parameters.

Wherein, the explosive parameters comprise explosive charging quantity Q (which can be converted from charging diameter 9), charging density p,,chemical energy E of unit mass explosive,

expansion index 7, of explosive products, charging length / and linear charging density q,; the plate parameters specifically contain minimum wall thickness d , density P, elastic constant FE, Poisson's ratio 4 and collapsing strength S ; the buffer layer parameters are thickness 6 , density p,, pressure parameter B, of state equation and adiabatic exponent 74 . When decoupled charging, the plates should be separated without redundant power.

The judging condition at this time is that the speed is V =0, and the relationship can be written as follows: V= F0 Po Ls Vos PE HS, À, pr, Bo, 7, 6) (ID), 0 = pap 2). q, = 2 Top’ 3). Choosing p,,E,,d as the basic quantities and the following dimensionless functional relationship can be gotten: fA (4). BP d Pe PE, PE Pe d Formula (4) can be simplified as: vo inks) or V = (25 (5). E} By substituting formula (3) into formula (5), people can get the following result of ô v-1($.5) ©)

Besides, the main control parameters in the process of plate separation only retain the explosive charging diameter ¢ , minimum wall thickness d of plates and thickness 6 of buffer layer.

Assuming that there are 5 levels for each impact factor, the number of experiments required is reduced from 5% to 5°. As a preferred option, the safe separation method of plates and the charging constitution specifically comprise plates, explosives, detonators, air-spaced layers, buffer layers, plastic sleeves and grooves.

Wherein, a circular hole is opened at the center of the plates and a buffer layer is placed in the circular hole with explosives placed inside.

Specifically, the explosive is a decoupled charging constitution with the explosive diameter smaller than the blasthole diameter.

An interval charging constitution is arranged between the explosive and the blasthole wall.

The decoupled charging constitution effectively realizes the sustained release of explosive energy and reduces the local damage of the explosion to the plates.

Grooves are notched on both sides of the central axis of the plates, which is conducive to the generation and spread of cracks.

The explosive is in an interval charging constitution, that is, there are interval charging constitutions between the explosives.

Further, a spacer layer is arranged between the explosives, which is composed of nonel tubes covered by plastic sleeves.

Compared with the prior art, the safe separation method of plates and the charging constitution provided by the invention have the following beneficial effects.

The main control parameters in the plate separation process are reduced to three through theoretical deduction, so that the experimental process is simplified, and the number of experiments is reduced.

Further, the decoupled charging constitution in the circular hole of the plate can slowly release the explosive energy and reduce the local damage of the plates caused by the explosion. Grooves are notched on both sides of the central axis of the plates, which 1s beneficial to the generation and spread of cracks. The explosives are charged at intervals in the hole, so that the plates are separated safely without redundant power, thus ensuring the safety of the experimental process.

BRIEF DESCRIPTION OF THE FIGURES Figure 1 is a schematic diagram of the charging constitution in the invention. Figure 2 is a schematic diagram of the groove in the plate based on the safe separation method of plates and the charging constitution. In figures, 1- plate; 2- explosive; 3 - detonator; 4- spacer layer; 5- buffer layer; 6- groove.

DESCRIPTION OF THE INVENTION Embodiment 1 With reference to Fig. 1, the plate (1) is a titanium alloy plate with a length of 120mm, a width of 66mm and a height of 12mm. Referring to Fig. 2, the grooves (6) with a length of 120mm, a width of 0.5mm and a depth of Imm are respectively notched on both sides of the central axis of the plate (1). A circular hole with a diameter of 8mm and a length of 120mm is drilled in the center of the plate (1). Besides, the minimum wall thickness of the plate (1) is 2mm. The buffer layer (5) 1s a PVC pipe with a length of 120mm and a thickness of 1.5mm, and the buffer layer (5) is further placed in the central circular hole of the plate (1). Explosive (2) is 25mm long. The spacer layer (4), 20mm long, is composed of nonel tubes covered by plastic sleeves, and it is placed between the explosives (2). The explosive (2) is detonated by the detonator (3).

As described in the above embodiment, after the explosive (2) was detonated by the detonator (3), the spacer layer (4) transferred the shock wave, so that the subsequent explosives (2) were detonated in turn.

Then the explosive energy was slowly released by the buffer layer (5), and the local damage of the explosion to the plate (1) was reduced.

Under the induction of the grooves (6), the high-temperature and high-pressure gas produced by the explosion safely separated the plate (1) without giving it redundant power.

Compared with the existing plate separation method, the proposed method reduces the main control parameters in the plate separation process to three through theoretical deduction, which simplifies the experimental process and reduces the number of experiments.

Moreover, the decoupled charging constitution in the circular hole of the plate can slowly release the explosive energy and reduce the local damage of the plates caused by the explosion.

Grooves are notched on both sides of the central axis of the plates, which is beneficial to the generation and spread of cracks.

The explosives are charged at intervals in the hole, so that the plates are separated safely without redundant power, thus ensuring the safety of the experimental process.

Embodiment 2 When the length of the spacer layer (4) is 0, the charging constitution in the hole of the plate (1) is a continuous charging constitution.

The rest of the operations are similar to the Embodiment 1 and will not be repeated here.

It is obvious to those skilled in the field that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be realized in other specific forms without departing from the spirit or basic characteristics of the present invention.

Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive.

The scope of the present invention 1s defined by the appended claims rather than the foregoing description.

Therefore, it is intended that all changes falling within the meaning and scope of equivalent elements of the claims are included in the present invention.

Any reference mark in the figures shall not be regarded as limiting the claims concerned.

In addition, it should be understood that although this specification is described according to embodiments, each embodiment does not contain only one independent technical solution.

The description of this specification is only for the sake of clarity, and those skilled in the field should take the specification as a whole.

The technical solutions in each embodiment can also be combined appropriately to form other embodiments that can be understood by those skilled in the field.

Claims (2)

CLAIMS:

1. A plate safe separation method, characterized in that the based on theoretical derivation, the 13 control parameters in the process of plate separation are reduced to 3: assuming that each impact factor has 5 levels, it is equivalent to reducing the number of experiments from 53 to 5%; the theoretical derivation is described as follows: the main control parameters of plates’ fracture during explosion include explosive parameters, plate parameters and buffer layer parameters, wherein the explosive parameters comprise explosive charging quantity Q (which can be converted from charging diameter ?), charging density p,,chemical energy E of unit mass explosive, expansion index 7, of explosive products, charging length / and linear charging density q,; the plate parameters specifically contain minimum wall thickness d , density po, elastic constant FE, Poisson's ratio 4 and collapsing strength S ; the buffer layer parameters are thickness & , density p,, pressure parameter B, of state equation and adiabatic exponent 7 ; when decoupled charging, the plates should be separated without redundant power; the judging condition at this time is that the speed is V =0, and the relationship can be written as follows: Vf por Eos Ves PE MSA, pp By, 74, 6) (1, 0 = x ppl (2), q, = 2 Top’ (3);

choosing p,,F,,d as the basic quantities and the following dimensionless functional relationship can be gotten: fA (4); BP d Pe PE PE Pe d Formula (4) can be simplified as: ur od) 6 E} by substituting formula (3) into formula (5), people can get the following result of ô V = f 2. (6) ; besides, the main control parameters in the process of plate separation only retain the explosive charging diameter ¢ , minimum wall thickness d of plates and thickness 6 of buffer layer; assuming that there are 5 levels for each impact factor, the number of experiments required is reduced from 5% to 5°.

2. A charging constitution matched with the plate safe separation method as stated in Claim, characterized by comprising plates, explosives, detonators, buffer layers, plastic sleeves and grooves, wherein a circular hole is drilled at the center of the plates and grooves are notched on both sides of the central axis of the plates, with the same length as the plate, a depth of 0.5mm, and a width of 1mm; the buffer layer is placed in the circular hole with explosives placed inside; further, the spacer layer is arranged between the explosives, which is composed of nonel tubes covered by plastic sleeves; the explosives are detonated by the detonator.