CN-121973296-A - Low-damage secondary energy-gathering jet cutting device for fiber composite material

CN121973296ACN 121973296 ACN121973296 ACN 121973296ACN-121973296-A

Abstract

The invention relates to a low-damage secondary energy-gathering jet cutting device for a fiber composite material. The explosive-proof device comprises a buffer protective cover, a linear cutter module, a shaped explosive-collecting module and an explosion-proof body arranged between the linear cutter and the shaped explosive-collecting module, wherein the shaped explosive-collecting module is composed of a plurality of miniature shaped explosive-collecting units which are linearly arranged and used for pre-puncturing a row of pre-guide holes to form a continuous stress concentration line and crack propagation pre-manufactured path, and the linear cutter module is used for carrying out delayed detonation and finishing final cutting along the pre-manufactured path. The invention is guided by the prefabricated stress concentration point, the subsequent cutting mode is controlled in time sequence, the problems of material tearing, layering, rough cutting boundary and the like are improved through the cooperative mechanism of the pre-guiding and the post-cutting, the smoothness and the quality of a cutting surface are improved, the problem of fiber damage is reduced, and the invention has wide application prospect in the precise cutting of high-performance composite materials such as carbon fibers, kevlar and the like used in the fields of aerospace, rail transit, high-performance ships and the like.

Inventors

ZHANG XIANFENG
ZHANG YUHUI
TAN MENGTING
CAO RENJIE
XIONG WEI
LIU CHUANG

Assignees

南京理工大学

Dates

Publication Date: 20260505
Application Date: 20260130

Claims (10)

1. A low-damage secondary energy-gathering jet cutting device for fiber composite materials, which is characterized by comprising a buffer protection cover (1), a linear cutter module, a shaped charge module and an explosion-proof body (3) arranged between the linear cutter module and the shaped charge module; The shaped charge module is composed of a plurality of miniature shaped charge units which are linearly arranged and used for pre-puncturing a row of pre-guide holes to form a continuous stress concentration line and a crack propagation pre-fabricated path; and the linear cutter module delays detonation and completes final cutting along the prefabricated path.
2. Cutting device according to claim 1, characterized in that the linear cutter module comprises a housing I (7), a linear cutter cartridge (8), a linear liner (9) and a fuze; Also comprises a locating plate (5) and a fixing plate (6), The locating plate (5) is provided with a threaded hole, each miniature shaped charge unit is in threaded connection with the locating plate (5) through external threads of the shell II (12), and two ends of the locating plate (5) are fixedly connected through bolts of the fixing plate (6) and the buffer protection cover (1).
3. Cutting device according to claim 2, characterized in that each micro shaped charge unit comprises a fuze (11), a housing II (12), a shaped charge grain (13) and a cone shaped liner (14), the fuze (11) being electronically time-lapse initiation controlled for controlling the initiation of the shaped charge module (4) prior to the initiation of the linear cutter module (2).
4. A cutting device according to claim 3, characterized in that the flame-proof body (3) is of a piston-type construction with lateral pressure relief channels.
5. A cutting device according to claim 3, characterized in that the buffer protection cover (1) is made of foamed metal or high damping polymer material for absorbing detonation shock waves and restraining fragments, the buffer protection cover (1) and the body to be cut are fixed by adopting a detachable mechanical connection mode; the linear shaped charge liner (9) and the conical shaped charge liner (13) are made of copper, titanium alloy or copper alloy; the shell I (7) and the shell II (12) are made of steel or high-strength aluminum alloy; the linear cutter module adopts an end detonating mode, and the shaped charge module adopts a center synchronous detonating mode; The positioning plate (5) adopts low damping polymer to position and control the distance of the shaped charge modules (4).
6. A cutting device according to claim 3 wherein the radius r, depth h and spacing d of the pilot holes of the preformed path formed by the shaped charge modules are determined by: , Where r is the radius of the guide hole, typically H is the depth of the guide hole, d is the distance between the guide holes, T is the thickness of the belt cutting plate, B is the width of the pre-cutting path, and the width satisfies K is expansion coefficient of the damaged area and represents the outer radius of the damaged area The ratio to the radius r of the guide hole is reduced by 1, i.e The composite material is generally obtained by taking 0.5-2 and measuring through a test; firstly, determining the radius r and depth h of a guide hole, controlling the loading and the explosion height of the guide hole by the depth h of the guide hole, forming a continuous weakening surface in the thickness direction of the target depth, and judging the satisfaction relation according to an empirical formula And calculating the guide hole distance D from the damage factor D relation: , the upper limit d opt of the pilot hole spacing d is calculated according to the following equation: , Wherein, the The method comprises the steps that net stress generated between holes for main cutting load, namely dynamic tensile stress peak value caused by impact of stress wave generated by a rear-stage linear cutter and front-stage jet flow on ligament area between pre-guide holes is obtained by sticking dynamic strain gauge records on the ligament area between the pre-guide holes; Is a geometric correction factor.
7. The cutting device of claim 6 wherein each micro shaped charge unit charge radius Calculation according to engineering empirical formula Wherein The value range is 3-5 for the empirical coefficient; the drug loading N is calculated based on the constant penetration theory according to the depth h of the guide hole, namely Wherein For depth factor, for typical carbon fiber board, PETN based explosives, red copper liner, ; Cone angle of liner Adopts a large cone angle to meet Wherein The jet flow divergence angle is 0-8 degrees for the liner with the cone angle of 60-120 degrees; Liner wall thickness of shaped charge structure The method meets the following conditions: wherein Is an empirical coefficient, has a value of 0.015-0.03, In order to achieve the density of the explosive, Is the detonation velocity of the explosive, Is dynamic flow stress of the liner at high pressure and high strain rate.
8. The cutting device of claim 7, wherein the effective specific kinetic energy of the cutting jet of the linear cutter module Greater than the dynamic specific separation energy required for separation of the material along the pre-guide path The characteristic is as follows: , Wherein, the For the kinetic energy component of the jet perpendicular to the target plate direction, Is the action area, and maximizes the action area by optimizing the geometry and the detonation mode of the shaped charge liner Realizing the efficient cutting with the minimum main charge energy; According to the effective specific kinetic energy Determining linear cutter charge linear density , The value range is 0.15-0.25 for the energy conversion efficiency, and Q is the specific energy of the explosive; Linear cutter liner density For the wall thickness of the shaped charge liner Wherein Is the density of the shaped charge liner; the cone angle is within the range of 。
9. The cutting device of claim 8, wherein the minimum safe thickness of the flameproof body Based on a one-dimensional stress wave attenuation theory, the impact initiation critical conditions of the subsequent-stage charge are required to be met, namely: , Wherein, the For the initial percussion pressure of the front-stage interface, Is the damping coefficient of the explosion-proof body material, n is the geometric damping factor, The detonation critical pressure is the impact of the rear-stage explosive, and x 0 is the distance between the detonation face of the flameproof body and the detonation position; Delay of fuze (11) Satisfy the following requirements Wherein k is a safety coefficient, and the value range is 1.2-1.5; Effective action time Wherein Obtaining the stress wave arrival time and the damage completion time as empirical parameters through experiments, and the propagation time S is the distance traveled by the stress wave, i.e., the distance between the linear cutter module and the center of action of the shaped charge module, and C is the average wave velocity in the material.
10. A cutting device according to any one of claims 1 to 9, wherein the cutting device is curved overall and a plurality of cutting devices are joined end to end in an endless path in a unitary structure for circumferential cutting.

Description

Low-damage secondary energy-gathering jet cutting device for fiber composite material Technical Field The invention belongs to the technical field of composite material processing, and particularly relates to a low-damage secondary energy-gathering jet cutting device for a fiber composite material. Background Fiber reinforced composites, particularly carbon fiber composites and basalt fiber composites, have become key material systems for weight reduction and synergy of modern high-end industrial equipment by virtue of their high specific strength, high specific modulus and excellent fatigue resistance and designability. Its application has been ranging from the aerospace field, the method is widely applied to the fields of critical components such as new energy automobile bodies, rail transit carriages, high-performance ship shells, precise closed pressure containers and the like, which have strict requirements on light weight and performance. With the deep application, the characteristic of relatively weak anisotropism, non-uniformity and interlayer strength also brings serious challenges to mechanical processing, particularly to a cutting separation process. When the traditional mechanical cutting (such as cutter cutting and mechanical hole turning) or the non-traditional cutting (such as water jet and laser) is used for processing the materials, a series of damage defects are extremely easy to cause, the damage such as fiber tearing, layering and burrs is extremely easy to occur, the quality of a cutting boundary is difficult to control, and the usability, the safety and the reliability of a component are directly affected. To address the challenges described above, the industry explored a variety of cutting techniques. The linear energy-collecting cutter is used as a high-efficiency separation device, and the explosive detonation is utilized to drive the shaped charge cover to form high-speed metal jet flow, so that penetration cutting of target materials is realized, and the linear energy-collecting cutter has the advantages of concentrated energy, extremely short acting time, non-contact and the like. However, conventional linear energy harvesting cutters are extremely sensitive to frying height, loading parameters, etc. when cutting composite materials. If the parameters are improperly matched, the formed jet flow may be insufficient or excessive in penetration, so that rough cuts and edge tearing are caused, and even large-area interlayer peeling is caused by stress wave reflection, the action mechanism is focused on penetration-tearing, and controllable separation of a sensitive structure of the composite material is difficult to realize. In summary, the prior art has difficulty in achieving a good balance between "high efficiency", "low damage" and "strong adaptability" when cutting fiber reinforced composites. Although the linear energy-gathering cutter has high efficiency, the quality of the cutting boundary is not easy to control, and the composite material is easy to be damaged by tearing and the like, and some precise cutting methods have limitations in efficiency or applicable scenes. Therefore, a new scheme for cutting and separating composite materials is urgently needed to realize accurate prefabrication and guiding of crack propagation paths of the composite materials, so that the original performance of the materials is reserved to the maximum extent while the composite materials are efficiently separated, and urgent requirements of high-quality, low-damage and controllable manufacturing processes in the high-end industrial field are met. Disclosure of Invention The invention aims to provide a low-damage secondary energy-gathering jet cutting device for a fiber composite material, which aims to solve the problems of fiber tearing, layering, rough cutting surface and the like in the cutting process by the cooperation and release of secondary energy from a traditional cutting 'passive penetration-tearing' mode or a preset defect mode to an 'active guiding-separating' mode, and realize smooth cutting with high quality and low damage. The technical scheme for realizing the aim of the invention is that the low-damage secondary energy-gathering jet cutting device for the fiber composite material comprises a buffer protection cover, a linear cutter module, a shaped charge module and an explosion-proof body arranged between the linear cutter module and the shaped charge module; The shaped charge module is composed of a plurality of miniature shaped charge units which are linearly arranged and used for pre-puncturing a row of pre-guide holes to form a continuous stress concentration line and a crack propagation pre-fabricated path; and the linear cutter module delays detonation and completes final cutting along the prefabricated path. Further, the linear cutter module comprises a shell I, a linear cutter grain, a linear liner and a fuze; also comprises a positioning plate and a fixing plate, Th