Model construction method for speed of metal plate driven by composite charge detonation

Abstract

The invention relates to a model construction method for the speed of a composite charge detonation driving metal plate, belongs to the technical field of composite charge overpressure detonation, and solves the problem that the driving rule of a composite charge structure is not comprehensive due to the lack of theoretical calculation and analysis of parameters of the composite charge driving metal plate in the prior art. Comprising the following steps: determining each movement time period of a metal plate based on each detonation process stage in a composite charge detonation process and initial parameters of composite charge; based on the detonation process stage of each movement time period of the metal plate, obtaining composite charge internal flow field parameters and detonation incident angles in each movement time period; and obtaining the speed of the metal plate in each motion time period based on the internal flow field parameter of the composite charge in each motion time period, the initial parameter of the composite charge and the detonation incidence angle, and completing the model construction of the speed of the metal plate. The speed of the composite charge overpressure detonation driving metal plate is determined, and technical support is provided for research and development of composite high-energy charge structure design, detonation wave superposition driving enhancement and the like.

Description

Technical Field

[0001] The invention relates to the technical field of composite charge overpressure detonation, and in particular to a method for constructing a model of composite charge overpressure detonation driving metal plate velocity. Background Art

[0002] In recent years, under the guidance of asymmetric warfare concepts, the main charge of the warhead is not expected to explode completely in urban warfare or peacekeeping operations. The first is to reduce collateral damage and the second is to avoid the escalation of conflicts. Therefore, the controllable composite warhead, which can improve the combat adaptability and flexibility and reduce the logistical burden, has become one of the current research hotspots. The composite charge warhead can select the damage effect of the weapon according to different target types, thereby improving the battlefield use flexibility of the weapon and realizing the energy output of the composite charge in the controllable warhead. With the widespread application of new composite structure warheads, how to accurately describe the dynamic evolution of the symmetrical collision zone of the internal flow field of the composite charge and the working ability of the composite charge and other related issues have become the difficulties and hotspots of research in the field of engineering applications.

[0003] At present, the research focus of the calculation of flow field parameters after the internal explosion of composite charge is on the two aspects of experiment and simulation. Among them, the theoretical research is mainly based on the isentropic theory of explosives under ideal conditions, so as to characterize the dynamic mechanical physical parameters of the products in the collision zone of explosive detonation reaction. However, due to the strong impact of explosives under different charge structures and detonation methods, the convergence and superposition of detonation waves cause the explosives to exceed their critical detonation conditions, so that the state of the detonation products deviates from the main isentropic line, and the flow field parameters such as pressure and velocity are much higher than the normal CJ ​​detonation state, thus producing an overpressure detonation phenomenon, making the state equation used to describe the ideal explosive detonation products no longer applicable. In addition, there is little theoretical research on explosives under overpressure detonation conditions, especially the lack of theoretical calculation and analysis of the parameters of the metal plate (also called flyer) driven by the new composite charge. The driving law of the composite charge structure is not comprehensive enough, and the axial drive and working ability of the composite charge cannot be further analyzed. Summary of the invention

[0004] In view of the above analysis, an embodiment of the present invention aims to provide a theoretical calculation method for the speed of a metal plate driven by overpressure detonation of a composite charge, so as to solve the problem that the driving law of the composite charge structure is not comprehensive due to the lack of theoretical calculation and analysis of parameters of the composite charge driven metal plate in the prior art.

[0005] The embodiment of the present invention provides a method for constructing a model of the speed of a metal plate driven by overpressure detonation of a composite charge, comprising the following steps: Determine each movement time period of the metal plate based on each detonation process stage and initial parameters of the composite charge during the detonation process of the composite charge; wherein the composite charge detonation time is taken as the initial time, and the initial parameters include the length of the composite charge, the diameters of the inner and outer layers of the charge, and the detonation velocities of the inner and outer layers of the charge; Based on the detonation process stage of each moving time period of the metal plate, the internal flow field parameters and detonation incident angle of the composite charge in each moving time period are obtained; Based on the internal flow field parameters of the composite charge in each movement time period, the initial parameters of the composite charge and the detonation incident angle, the velocity expression of the metal plate in each movement time period is obtained, and the model construction of the metal plate velocity is completed.

[0006] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects: The present invention provides a method for constructing a model of the speed of a metal plate driven by overpressure detonation of a composite charge. 1. The motion characteristics of the metal plate at any time in the overpressure detonation of the composite charge are constructed, and the speed of the metal plate at any time can be obtained. The driving law of the composite charge structure can be described by the motion of the metal plate, which can effectively evaluate the work performance of the composite charge, provide technical support for the in-depth study of the energy release rate of the composite charge and the structural optimization design, and also provide technical support for the research and development of composite high-energy charge structure design technology, detonation wave superposition drive enhancement technology, and a new generation of directional killing warheads; 2. Considering the interaction between oblique shock waves and rarefaction waves generated inside the composite charge during the detonation process, a theoretical calculation method for the internal flow field parameters of the composite charge was established. By partitioning and deriving the temporal and spatial relationship of the pressure and other physical parameters acting inside the composite charge detonation products over time, the internal parameters of the explosive after overpressure detonation can be accurately analyzed, and the theoretical closure of the interaction parameters of the detonation waves of condensed explosives has been achieved. This method has wide applicability, high accuracy, and strong stability. It can be used to characterize the theoretical calculation model of explosives under overpressure detonation, laying a foundation for studying the internal detonation reaction mechanism, driving damage model, and energy output response law of composite charges.

[0007] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The accompanying drawings are only used for the purpose of illustrating specific embodiments and are not to be considered as limiting the present invention. In the entire drawings, the same reference symbols represent the same components; Figure 1A schematic flow chart of a method for constructing a model of the speed of a metal plate driven by a composite charge detonation provided in an embodiment of the present invention; Figure 2 A schematic diagram of a composite charge detonation wave process provided by an embodiment of the present invention; Figure 3 A schematic diagram of a composite charge detonation wave structure provided in an embodiment of the present invention; Figure 4 A schematic diagram of the flow near the collision point of a regular reflected detonation wave provided by an embodiment of the present invention; Figure 5 A schematic diagram of the flow of a medium before and after an oblique shock wave provided by an embodiment of the present invention; Figure 6 A schematic diagram of a polar curve of pressure and rotation angle provided by an embodiment of the present invention; Figure 7 A schematic diagram of solving a shock wave regular oblique collision polar curve provided by an embodiment of the present invention; Figure 8 The pressure and rotation angle polar curves of the reflected wave at different incident angles provided by the embodiment of the present invention; Fig. 9 A schematic diagram of flow field parameter distribution near the collision point of an irregular oblique reflection detonation wave provided in an embodiment of the present invention; Fig.10 A schematic diagram of the wave system development within a certain time interval of the collision of the irregular oblique reflection detonation wave provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0009] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0010] A specific embodiment of the present invention discloses a method for constructing a model of the speed of a metal plate driven by a composite charge detonation, such as Figure 1 As shown, the following steps are included: S1. Determine each movement time period of the metal plate based on each detonation process stage during the propagation of the composite charge detonation and the initial parameters of the composite charge; wherein the detonation moment of the composite charge is taken as the initial moment, and the initial parameters include the length of the composite charge, the diameters of the inner and outer charges, and the detonation velocities of the inner and outer charges.

[0011] Specifically, Figure 2The composite charge detonation wave process shown in the figure, in this embodiment, first determine the conditions for the composite charge explosive to have an overpressure detonation, that is, determine the detonation incident angle when Mach reflection occurs, and divide the reaction process of the composite charge into regular oblique reflection and irregular oblique reflection according to the interaction relationship between the reflection angle and the incident angle. Thus, the detonation process stage includes regular oblique reflection process and irregular oblique reflection process. When the composite charge detonation develops to a certain stage, the detonation wave will not collide on the charge axis, and the detonation wave propagates as a stable plane wave. At this time, the detonation process stage is in a stable detonation propagation process. At this time, the metal plate follows the one-dimensional detonation drive theory. Thus, the movement process of the metal plate is divided.

[0012] During implementation, the detonation process stages include regular oblique reflection process, irregular oblique reflection process and stable detonation propagation process; among them, The movement time period of the metal plate corresponding to the regular oblique reflection process is ; The movement time period of the metal plate corresponding to the irregular oblique reflection process is ; The motion time period of the metal plate corresponding to the stable detonation propagation process is ; in, represents the moment of motion of the metal plate, It represents the motion moment of the metal plate when the detonation incident angle is the Mach critical angle, It represents the metal plate motion moment corresponding to when the composite charge detonation products enter into stable plane wave propagation.

[0013] In specific implementation, the corresponding metal plate motion moment when the detonation incident angle is the Mach critical angle is It is expressed as: , The corresponding metal plate motion moment when the composite charge detonation product enters the stable plane wave propagation It is expressed as: , in, ; In the formula, , Respectively represent the diameters of the outer and inner layers of the composite charge, , Respectively represent the detonation velocity of the outer layer charge and the inner layer charge of the composite charge, Indicates the length of the composite charge.

[0014] It should be noted that when the detonation incident angle satisfy When the detonation incident angle is satisfy When , the detonation process of the composite charge belongs to an irregular oblique reflection process; represents the Mach critical angle. The detonation incident angle is This means that the detonation wave is incident perpendicular to the interface. In this case, no reflection occurs, but the wave passes directly through the interface and continues to propagate along the original path. The detonation incident angle is This means that the detonation wave is incident parallel to the interface. In this case, the detonation wave will not enter the other medium of the interface, but will propagate along the surface of the interface. Therefore, in this embodiment, the composite charge structure has a difference in detonation velocity between the inner and outer layers. This is the moment when the composite charge begins to detonate. The detonation wave has not yet propagated to the metal plate, that is, the speed of the metal plate is 0 at this time.

[0015] S2. Based on the detonation process stage of each movement time period of the metal plate, the internal flow field parameters and the detonation incident angle of the composite charge in each movement time period are obtained; Specifically, based on the physical parameter expression of the composite charge in each partition, the relationship between the variation of each physical parameter of the composite charge with the incident angle from the beginning of detonation to the convergence of the detonation wave is obtained; wherein, based on The state equation theoretically calculates the flow field parameters in the regular oblique reflection process of the composite charge, and then obtains the functional relationship between the Mach reflection pressure and the Mach reflection critical angle by inverting and calibrating the slow-varying coefficient based on the Whitham method, and theoretically calculates the pressure when irregular oblique reflection occurs inside the composite charge model. In the regular oblique reflection process and irregular oblique reflection process, the calculation of the flow field parameters is closely related to the detonation incident angle. Combined with the characteristics of the composite charge itself, the detonation incident angles at each moment in the regular oblique reflection process and irregular oblique reflection process are given as follows: When implemented, When , the detonation incident angle satisfies the following formula: , In the formula, Indicates at time The detonation incident angle at .

[0016] It is understandable that when When , there is no superposition of detonation waves, and the inner and outer charges of the composite charge drive the metal plate at the same detonation speed. At this time, the metal plate follows the one-dimensional detonation driving theory.

[0017] S3. Based on the internal flow field parameters of the composite charge in each movement time period, the initial parameters of the composite charge and the detonation incident angle, the velocity expression of the metal plate in each movement time period is obtained to complete the model construction of the metal plate velocity.

[0018] Specifically, by utilizing the instantaneous detonation theory and one-dimensional dispersion theory, a model based on the instantaneous driving speed of the metal plate by the composite charge is established. That is, the motion characteristics of the metal plate at any time are constructed, and the driving performance of the composite charge can be evaluated.

[0019] When the metal plate moves for When the composite charge is in the detonation process stage, it is in the regular oblique reflection process, which includes the undetonated area of ​​the explosive, the detonation product area and the post-reflection shock wave state area. During this motion period, the metal plate moves at a speed of Movement, speed of the metal plate It is expressed as: , In the formula, Indicates at time The detonation product pressure in the state area after the reflected shock wave is is the cross-sectional area of ​​the metal plate, Indicates the mass of the metal sheet.

[0020] In a specific implementation, the pressure of the detonation products in the state area after the reflected shock wave is It is expressed as: , In the formula, It represents the specific volume of the detonation products of explosives in the CJ state, Indicates the explosion pressure of explosives in CJ state, represents the velocity of the flow mass in the detonation product zone, , represent the density and specific volume of the detonation products in the state after the reflected shock wave, It represents the deflection angle of the flow mass in the state area after the reflected shock wave.

[0021] Specifically, the velocity of the flow mass in the detonation product zone is It is expressed as: , In the formula, It represents the detonation velocity of the detonation products in the CJ state of the explosive, represents the detonation incident angle, Represents the cotangent function.

[0022] Specifically, the density of the detonation products in the state area after the reflected shock wave is It is expressed as: , Specifically, the flow group deflection angle in the state area after the reflected shock wave It is expressed as: , Specifically, the specific volume of the detonation products in the state area after the reflected shock wave is By combining the following formulas, we get: , In the formula, represents the charge density of the composite charge, , , , , , , They are The constant coefficients of the state equation, represents the multi-party index, It represents the specific internal energy of the detonation products in the CJ state of the explosive.

[0023] More specifically, ,in, Represents the initial specific volume of the composite charge.

[0024] More specifically, the multi-party index It is expressed as: , in, , In the formula, represents the total adiabatic index, represents the total number of components in the composite charge, Indicates the first The amount of component substance, Indicates the first The mass fraction of the component, Indicates the first The molar mass of the component, Indicates the first Adiabatic index of the component. It can be appreciated that the polytropic index obtained in this way is more accurate.

[0025] It should be noted that the speed of the metal plate during this motion period is obtained through the following analysis: When the metal plate moves At this time, due to the different degrees of shock compression of the high and low detonation waves in the inner and outer layers of the composite charge and the newly formed detonation wave, the pressure and particle velocity of the convergence area after the original two shock waves will not be the same as the pressure and particle velocity of the overpressure detonation area after the newly formed shock wave, so a reflected wave will also be generated to adjust the contradiction between the unequal pressure and velocity between the two areas. At the same time, if Figure 2As shown in the figure, when the incident wave converges to the center, there is a phenomenon that the reacted area of ​​the outer layer of high detonation velocity explosive in the composite charge forms a lateral detonation phenomenon from the vertical direction to the unreacted area of ​​the inner layer of low detonation velocity explosive, and the detonation waves of the inner and outer layers of charge are coupled to form an overall converging waveform. According to Newton's second law, the velocity of the metal plate in this time period can be obtained, where Newton's second law is expressed as: , When the metal plate moves for The composite charge detonation process is in the irregular oblique reflection process, which includes the undetonated area of ​​explosives, the detonation product area, the post-reflection shock wave state area and the post-Mach wave state area. The speed of the metal plate in this motion period is It is expressed as: , In the formula, represents the Mach wave velocity in the post-Mach wave state region, represents the speed of sound of the detonation products in the post-Mach wave state, Represents the dynamic rigidity index of the metal sheet material, represents the length of the post-Mach wave state region, represents the pressure of the detonation products in the post-Mach wave state region, represents the initial particle velocity of the Mach wave acting on the metal plate medium.

[0026] Specifically, the pressure of the detonation products in the post-Mach wave region is , obtained by the following formula: , in, represents the slow-varying coefficient, represents the detonation incident angle.

[0027] Specifically, the initial particle velocity of the Mach wave acting on the metal plate medium is , obtained by the following formula: , In the formula, , Represent the first and second material compression coefficients, respectively. represents the pressure of the metal plate medium acting on the Mach wave, represents the multi-party index, Represents the initial density of the metal sheet material.

[0028] Specifically, the dynamic rigidity index of the material It is expressed as: , in, , In the formula, It represents the ratio of the shock wave impedance of the material and the explosive, represents the initial velocity of the explosion shock wave in the metal plate medium, , represent the first dielectric coefficient and the second dielectric coefficient of the metal plate respectively.

[0029] Preferably, the metal plate is a copper metal plate. , , .

[0030] Specifically, the speed of sound of the detonation products in the post-Mach wave region is It is expressed as: , in, , In the formula, represents the initial internal energy per unit volume.

[0031] Specifically, at the time Mach wave speed It is expressed as: , in, , In the formula, Represents the three-point wave growth angle.

[0032] Specifically, in The length of the post-Mach wave state zone at time is the three-point wave growth angle at the corresponding moment in the three-point wave trajectory The horizontal coordinates of the corresponding three wave points.

[0033] It should be noted that the speed of the metal plate during this motion period is obtained through the following analysis: Using the initial and boundary conditions, that is, when When the explosion wave propagates to a certain distance and angle, the offsetting effect of the reflected shock wave is not enough to turn the flow field back. When it encounters a solid wall or interface, it will reflect and generate a higher pressure. The sharply increased pressure will produce Mach reflection in the axisymmetric internal contraction flow field. Based on the local isentropic assumption, in the micro-time domain In, we can get the following relationship: , In the formula, Represents the pressure acting on the wall of the metal plate.

[0034] Each wave in the right-propagating simple wave system behind the Mach wave is based on its own The velocity propagates to the right. When it reaches the wall of the metal plate, the particle velocity of the detonation product The speed that immediately becomes the metal plate wall , the speed of sound of the post-Mach wave detonation product Immediately becomes the speed of sound of the product at the wall , the pressure of the post-Mach wave detonation products Immediately becomes the pressure at the wall , and there are Therefore, the wall velocity of the metal plate is The changing rules are determined as follows: , , In the formula, represents the displacement of the metal plate.

[0035] in, , , In the formula, represents the initial internal energy per unit volume, Represents an isentropic calculation.

[0036] The motion law of the product at the metal plate wall can be calculated by the following empirical formula: , Among them, the length of the post-Mach wave state region is the growth angle of the three-point wave in the three-point trajectory The horizontal coordinates corresponding to the three wave points.

[0037] Among them, the initial particle velocity of the Mach wave acting on the metal plate medium is satisfy: , , , Solving equations (20), (21) and (22) together yields: , According to the movement speed of the metal plate wall: , from formula (22): , Transform equation (24) and integrate it to get: , Substituting equation (25) into equation (23), we obtain: , Substituting equation (26) into equation (20) and integrating it, the velocity of the metal plate during the motion period is expressed as: , During implementation, the inner layer of the composite charge is aluminum-containing explosive; when the metal plate moves for The composite charge detonation process is in a stable detonation propagation process. The metal plate speed in the metal plate movement period is It is expressed as: , in, , In the formula, Indicates the content of aluminum powder in the inner layer of aluminum-containing explosive in composite charge; represents the specific heat capacity of gas at constant volume, which is solved by the Kast average molar heat capacity at constant volume equation; represents the reaction rate of aluminum powder, represents the universal gas constant, It indicates the reaction heat of aluminum powder in the inner layer of aluminum explosive in the composite charge. represents the multi-party index, , It represents the specific volume and density of the detonation products during the propagation of stable detonation.

[0038] Preferably, , , .

[0039] It should be noted that the inner layer of the composite charge in this embodiment is aluminum-containing explosive, and the speed of the metal plate in this movement time period is obtained by the following analysis: when When , the detonation wave will not collide on the charge axis, and the detonation wave propagates as a stable plane wave, satisfying: , In the formula, represents the total pressure of the composite charge detonation products during the stable detonation propagation process, is the cross-sectional area of ​​the metal plate.

[0040] At this time, after the composite charge detonates, if the ideal components of the inner layer of aluminum explosives detonate instantaneously, the internal pressure and temperature of the detonation products will decrease as the detonation products continue to expand and diffuse. When the detonation products expand, assuming that the aluminum powder does not undergo a chemical reaction but only a physical reaction, then the internal pressure of the detonation products will decrease as the volume of the detonation products continues to increase. The state equation of the composite high-pressure gas expansion at this stage is: , in, , , In the formula, represents the pressure in the pressure decay equation of detonation products, It represents the initial specific volume of composite charge.

[0041] The reaction rate of the non-ideal components of the inner layer of aluminized explosive in the composite charge is the reaction rate of the aluminized explosive. The universal equation for aluminized explosive is the reaction rate equation related to pressure, which is expressed as follows: , In the formula, Indicates the reactivity of aluminum powder. Indicates the pressure of the detonation product of the inner layer of aluminum-containing explosive in the composite charge. is the specific energy of non-ideal detonation when non-ideal components of explosives in composite charges detonate.

[0042] in, is the specific energy of the non-ideal detonation when the non-ideal components of the explosive in the composite charge detonate. It can be seen that the energy released by the non-ideal components of the explosive in the composite charge has a maximum value, and as the reaction proceeds, the speed of energy release becomes smaller and smaller. When , the released energy reaches a maximum value (maximum value) and the reaction rate is zero.

[0043] According to formula (31), the variation of the heat release of aluminum powder reaction with time during the non-ideal detonation of the explosive in the composite charge can be obtained. The first and second order derivatives of the heat release formula (31) of aluminum powder reaction during the non-ideal detonation of the explosive in the composite charge are obtained. Under constant volume conditions, considering the time Changes to According to the relationship between heat and heat capacity in the first law of thermodynamics and the gas state equation, the heat released by the aluminum powder reaction is: , In the formula, represents the temperature of detonation products.

[0044] By combining equations (31) and (32), and sorting and integrally solving them under the conditions of constant volume and constant pressure, the pressure contribution equation of heat release of aluminum powder after non-ideal detonation of explosive in composite charge is obtained as follows: , In the formula, The pressure contribution equation representing the heat release of aluminum powder.

[0045] Through the analysis and research on the secondary reaction theory of explosives in composite charge, the total pressure of the detonation product of composite charge is: , According to formula (30) and formula (33), the detonation pressure of the composite charge during non-ideal detonation is obtained: for: , Substituting formula (35) into formula (29) and using Newton's second law to rearrange it, we can obtain: , The relationship between the speed and time of the metal plate driven by the composite charge detonation can be obtained by formula (36). By rearranging formula (36), the speed of the metal plate when the composite charge detonation drives the metal plate to move is obtained as: , In summary, the motion of the metal plate driven by the composite charge detonation is divided into three stages for solution, namely the detonation wave convergence stage, i.e., the regular oblique reflection process, the detonation wave overpressure detonation stage, i.e., the irregular oblique reflection process, and the composite charge motion stage with stable plane wave, i.e., the stable detonation propagation process. Combining formulas (4), (12), and (28), the model of the metal plate velocity driven by the composite charge detonation is obtained as follows:

[0046] It should be noted that the flow field parameters of the composite charge detonation process in the regular oblique reflection process and the irregular oblique reflection process are obtained through the following derivation process. The internal division of the composite charge is as follows: Figure 3 As shown: Based on the evolution law of the detonation wave collision zone of the explosive during the overpressure process, the conditions for the overpressure detonation of the explosive are determined. The core issue is to determine the critical angle when Mach reflection occurs. According to the relationship between the reflection angle and the incident angle, the reaction process of the explosive is divided into regular oblique reflection and irregular oblique reflection. Based on the physical parameters of the explosive in each partition, the physical parameter expression of the explosive in each sub-area is obtained, and the physical parameter expression in each partition is integrated to construct a theoretical calculation method for the flow field parameters of the explosive under overpressure detonation.

[0047] The detonation incident angle of the detonation wave of the composite charge satisfies When , the collision in the composite charge is a regular oblique collision.

[0048] The reaction zone of a regular oblique collision is divided into regions, such as Figure 4 As shown in the figure, the regular oblique collision of two detonation waves of equal intensity can be regarded as the regular oblique reflection of one side of the detonation wave on the rigid wall. The collision with the rigid wall generates an oblique shock wave, which is an unsteady process. The origin of the coordinate is taken at the collision point T, and the incident detonation wave front TI and the reflected shock wave front TR are regarded as plane waves. The physical image near the detonation wave collision point is as follows: Figure 4 shown.

[0049] Therefore, the entire detonation area is divided into three zones by the planes where the incident wavefront, reflected wavefront, and symmetry plane are located: Zone (0) is the unexploded charge zone, Zone (1) is the detonation product zone, and Zone (2) is the area behind the reflected shock wave. In the coordinate system where point T is stationary, the flow becomes a steady flow, and Zone 0 moves at the detonation velocity. Vertically into the detonation wave front TI, and the explosion products move at a speed of The vertical outflow detonation wave front TI enters the (1) area. Then the flow mass flows at another speed The reflected wavefront TR passes vertically. From the perspective of being parallel to the rigid wall, the (0) zone moves at a speed parallel to the rigid wall. Flows toward the incident detonation wave front TI, and then turns inward at an angle ,by The velocity flows toward the reflected shock wave front TR. The flow direction after passing through the reflected shock wave front turns another angle. , according to the wall conditions in zone (2), the flow velocity The direction is parallel to the rigid wall. At this time, the deflection angles of the outflow wavefronts TI and TR are equal, that is, So far, the detonation reaction zone of explosives under regular reflection conditions has been divided.

[0050] The flow field parameters in the (0) region are defined as follows: The charge density of the explosive is , the detonation speed is , the pressure of the detonation products , internal energy per unit volume , particle velocity , speed of sound ; (1) The density of the detonation product area is , the detonation speed is , the pressure of the detonation products , internal energy per unit volume , particle velocity , speed of sound ; (2) The area is the detonation product area with a density of , the detonation speed is , the pressure of the detonation products , internal energy per unit volume , particle velocity , speed of sound ; Among them, the flow field parameters in the (0) area are all known quantities.

[0051] For the physical parameter problem of the detonation wave collision zone under oblique collision conditions, the core problem is to solve the pressure-angle relationship behind the oblique shock wave. In order to study the high-pressure flow of the medium caused by the detonation wave, a relative coordinate system with an oblique shock wave fixed is adopted, with the following assumptions: Figure 5 The steady oblique shock wave discontinuity S shown in the figure is a curved and smooth wavefront that can always be considered as a plane near a point. The wavefront flow direction is taken as the x-axis, and the flow velocity of the shock wavefront is , the wavefront pressure is ; The flow velocity after the shock wave is , the post-wave pressure is The flow before and after the oblique shock wave can be decomposed according to the normal and tangential directions of the shock wave front. , represents the normal and tangential components of the wavefront flow velocity, , represents the normal and tangential components of the flow velocity behind the wave, Figure 5 middle , , and , , It represents the density, isentropic sound speed, and specific internal energy before and after the wavefront. Since there is no flow velocity at the tangential discontinuity, the pressure on both sides of the discontinuity is equal, but the entropy, density, and tangential velocity are discontinuous. There is a flow velocity at the normal discontinuity, but the mass flow and energy flow through the normal discontinuity must be conserved. From the conservation of mass and the conservation of the tangential component of momentum, the conditions for the continuity of the tangential velocity can be derived. Combined with the interface conditions, the relationship between the flow before and after the wavefront can be obtained.

[0052] From the conservation of mass across the discontinuity and the conservation of the tangential component of momentum, we know that: , In the formula, is the mass flow per unit time across the unit area discontinuity. From the tangential velocity continuity condition, we know that , according to the conservation of momentum: , According to the energy conservation across the discontinuity: , In the formula, is the energy released by a unit mass of fluid when it passes over the discontinuity. The wavefront pressure is , the wavefront density is The specific internal energy, The wavefront pressure is , the wavefront density is Specific internal energy.

[0053] From equations (38) and (39), we can obtain: , Substituting equation (41) into equation (40) yields the Hugoniot relation: , according to Figure 5 And formula (41) we get: , In the formula, is the oblique shock wave front S and wavefront velocity The angle between.

[0054] The normal velocity difference across the strong discontinuity is calculated by equation (41): for: , In order to obtain the pressure-rotation angle polar curve, select the direction of the x-axis and The y-axis is perpendicular to the right-hand system, and and is the unit vector in the corresponding direction, then Figure 5 have: , In the formula, and The post-wave velocity Components on the x and y axes.

[0055] From the momentum conservation equation (41), mass conservation equation (40) and tangential velocity continuity equation ,get: , Substituting equation (45) into equation (46), we have: , According to the tangential velocity continuity equation (45), we have: , According to formula (45), we have: , Comparing equation (48) and equation (49), and considering equation (47), we have: , Depend on Figure 5 Visible, vector Relative to vector Rotated Angle, this value is: , Substituting equation (47) and equation (50) into equation (51), we obtain: , According to equation (52) and the shock wave Hugoniot relation (42), we can eliminate , we can get the relationship between the pressure behind the wave and the rotation angle under the condition of known wavefront parameters, that is, From (52), we can see that each group The values ​​of correspond to two values ​​with opposite signs but equal values. value, so the polar curve is relative to Axisymmetric. There are two roots, one of which is , at which point the shock wave degenerates into a sound wave. The other root corresponds to ,at this time , the oblique shock wave turns into a detonation wave with positive collision; among them, is the maximum detonation product pressure.

[0056] Using the theoretical analysis method of shock wave polar curve, for a given The supersonic flow problem around a wedge of represents any angle of incidence; do The straight line intersects the polar curve at , and Point, discard The solution behind the non-shock wave and unstable solutions , solvable The weak dissection of the point directly Figure 6 Get the corresponding The value is used for solving the interaction problem of oblique shock waves in the future. The tangential discontinuity is used as the separation surface, and the pressure on both sides of the tangential discontinuity is equal and the velocity is parallel as the solution condition. Polar curves are particularly convenient in their solution.

[0057] The shock wave polar curve diagram is shown in Figure 7 , curve 1 is given by Point sent The shock wave extreme curve, curve 2 is Issued The shock wave polar curves intersect at points A and B. Usually, weak fragmentation (point A) is what we are looking for. When the shock wave is not too large, the two shock wave polar curves intersect, which belongs to the normal oblique collision range of the shock wave. The increase in angle, and As the absolute value of increases, the corresponding two polar curves become farther and farther apart, and finally the two polar curves change from intersecting to tangent, which is the limit case of the regular oblique collision of the shock wave. When the limit case is reached, If the angle increases further, the two polar curves will move away again, and there will be no intersection between the two. At this time, it will be transformed into an irregular oblique collision of the shock wave.

[0058] In summary, this paper mainly introduces how to solve the pressure-rotation angle relationship behind the oblique shock wave, and then based on The state equation calculates the flow field parameters of the above three regions. Figure 4 The relationship between the parameters from zone (0) to zone (1) in the figure is given in Figure 1. The parameters in zone (0) are all known. Assuming that the explosive reacts completely and the expansion of the detonation products is not considered within a very short time interval, the pressure of the detonation products in zone (1) is based on The state equation is of the form: , In the formula, , , , , , , They are The constant coefficients of the state equation, represents the multi-party index, , are the specific volume and internal energy per unit volume of the detonation products in zone (1), respectively.

[0059] Since the state of the detonation products in zone (1) satisfies the CJ state, the state parameters of the detonation products in zone (1) satisfy the isentropic condition, then: , In the tangential direction of the incident detonation wave TI, assuming the tangential velocity remains constant, , so the flow velocity in zone (1) is and Mach number for: , According to the geometric relationship before and after the incident detonation wave TI, we have: , Applying the trigonometric function change formula, we get: , Furthermore, considering the changing relationship between the parameters from area (1) to area (2), area (2) is the area after the oblique reflection shock wave. According to the pressure-rotation angle relationship (52) after the oblique reflection shock wave, for the oblique reflection shock wave TR, we have: , The regular oblique collision of two detonation waves of equal intensity can be regarded as the regular oblique reflection of one side of the detonation wave on the rigid wall. The detonation wave collides with the rigid wall at a certain angle, and the collision produces an oblique shock wave. This process is an unsteady process. For the convenience of studying the problem, the origin of the coordinate is taken at the collision point, and the incident detonation wave and the reflected shock wave are regarded as plane waves. The physical image near the collision point of the detonation wave is as follows: Figure 4 shown.

[0060] After the detonation wave, the movement direction of the detonation product, i.e. the medium in zone (1), is no longer parallel to the x-axis, but is deflected toward the x-axis by an angle , the wall must hinder the flow of detonation products, thus generating a reflected shock wave on the wall. When the detonation products pass through the reflected shock wave, their flow is deflected in the opposite direction and then flows along the wall. (2) The area meets The state equation is , In the formula, , are the specific volume and internal energy per unit volume of the detonation products in zone (2).

[0061] From the Hugoniot relationship: , Furthermore, combining the Hugoniot relationship and The state equation is: , Simplifying formula (29) we can get: , Arranged: , From the relative specific volume: , but , Based on this, the physical parameters of the flow field when the detonation products are transformed from region (1) to region (2) can be solved according to formulas (59)-(64), which can be obtained according to The state equation iteration method is used to solve the pressure of regular oblique reflection collision.

[0062] In summary, when solving the flow field parameters of the regular oblique reflection collision zone, the known parameters include: the charge density of the explosive , dynamite State equation parameters , , , , , , , , the initial specific internal energy of the explosive , Specific volume of explosive CJ detonation products , , explosive detonation velocity .

[0063] The Mach critical angle is determined by: The flow velocity is calculated from equations (55) and (57): and the incident wave TI, the flow group deflection angle , then combine the Hugoniot relation (60) and The state equation (59) is , substitute (61) into (65) to obtain , then Substituting into (65), the pressure after the reflected wave is calculated by formula (65): and flow mass deflection angle The display solution of The point is Figure 7 The polar curve of the reflected shock wave TR is obtained ; Polar curve pay The axis is at points a and b. According to Von Neumann's detached shock wave criterion, they are both weak shock wave solutions. Obviously, point a is the stable solution of regular oblique reflection. Increase to hour, Figure 8 The two points a and b in the above equation coincide with each other. Axis tangent ( Figure 8 Middle Curve ). According to Von Neumann's detached shock wave criterion, This is the critical angle of incidence for the transition from a regular oblique collision to a Mach collision.

[0064] The flow field parameters can be calculated by the following method: By combining equations (53) to (58), the flow field parameters from the detonation product zone (0) to the zone (1) can be solved: the zone (1) is the detonation product zone with a density of , the detonation speed is , the pressure of the detonation products , internal energy per unit volume , particle velocity , speed of sound Based on this, according to formulas (59)-(64), the flow field physical parameters of the detonation product from area (1) to area (2) can be solved: Area (2) is the detonation product area with a density of , the detonation speed is , the pressure of the detonation products , internal energy per unit volume , particle velocity , speed of sound .

[0065] The detonation incident angle of the composite charge detonation wave satisfies When , the collision in the composite charge is a non-regular oblique collision.

[0066] The irregular oblique collision of two equal-intensity detonation waves can be regarded as the irregular oblique reflection of one of the detonation waves on the rigid wall. Fig. 9 The regular oblique reflection, when the angle between the incident detonation wave front TI and the rigid wall , gradually increases, the flow turning angle of the flow mass passing through the incident detonation wave TI and the flow turning angle through the reflected shock wave TR When the detonation wave incident angle increases to the critical incident angle of Mach reflection When the velocity of the flow mass in the (2) area after the reflected shock wave is It can no longer be parallel to the rigid wall, resulting in the accumulation of material, forcing the reflected shock wave to move upward, and the incident detonation wave is at a certain distance from the rigid wall, that is, the collision point S moves to point T, forming a Fig. 9 The Mach reflection shown. As the detonation wave propagates, the height of the Mach rod continues to increase, and its pressure and velocity decrease rapidly. When the pressure and detonation velocity on the Mach rod decrease to the CJ value, the Mach reflection disappears and a normal detonation occurs.

[0067] For the convenience of research, the coordinate system with its origin at the collision point is still used to transform the flow into a steady flow. Fig. 9The point S is the collision point, the point T is the triple wave point, TI is the incident detonation wave front, TR is the reflected shock wave front, and TS is the Mach rod. The flow field near the triple wave point can be divided into four regions: the (0) region before the incident detonation wave TI and the Mach rod wave TS, that is, the non-detonation region, the (1) region after the incident detonation wave TI and before the reflected shock wave TR, that is, the detonation product region, the (2) region between the reflected shock wave TR and the contact discontinuity TQ, that is, the reflected shock wave post-state region, and the (3) region between the Mach rod TS and the contact discontinuity TQ, that is, the Mach wave post-state region.

[0068] The Mach bar is an over-compressed strong explosion wave, TS is a curved surface, and the angle between the tangent line at each point on it and the rigid wall is and At point S, the wavefront is perpendicular to the rigid wall, and at point T, the angle between the wavefront and the wall is The fluid behind point T comes from the (0) zone in front of the incident detonation wave and the Mach rod. Some of them pass through the Mach rod TS, and another part of the fluid first passes through the incident detonation wave TI and then passes through the reflected shock wave TR. Since the entropy increase across the shock wave is a third-order quantity of the pressure difference before and after the shock wave, starting from the same state, the entropy increase of a part of the flow group after a shock wave compression is , while the entropy increase of the other part of the flow group after two compressions is ,and ,in, , The first and second entropy increases during Mach reflection, so the entropy increase of the first compression is always greater than the entropy increase of the second compression, so the density of the detonation products after the reflected wave TR and after the Mach rod TS is different. In this way, there is a tangential discontinuity between the reflected wave and the Mach rod, which is called a contact discontinuity or slip line, represented by TQ.

[0069] Based on the Whitham method, the Mach rod is regarded as the result of the incident detonation wave propagating in a convergent variable cross-section flow tube and the Mach wave is simplified to a plane wave perpendicular to the rigid wall. In the two-dimensional case, the position of the detonation wave is the same as the position of the ray perpendicular to it. Fig.10 middle and There is a variable cross-section pipeline between the two lines; represents the angle of incidence, Represents the reflection angle. OR is The incident detonation wave position at time, for The Mach rod is transformed from the incident detonation wave OR at the moment. When Mach reflection occurs, a curved surface reflection shock wave and Mach wave are formed. The Mach wave OM is perpendicular to the rigid wall (such as Fig.10 ), is the detonation wave incident angle , Three wave point growth angle .exist During this time, the three-wave point O moves to . At the "three wave points" The motion of the incident wave and the reflected wave above is independent. In this process, the incident wave and the reflected wave meet, that is, the reflected wave catches up with the incident wave, and a composite wave, namely the Mach wave, is generated. For a medium with normal compressibility, this view is reasonable. Points L and Y in the figure are the intersection points of the extended lines of the incident and reflected waves and the parallel lines of the rigid wall, respectively.

[0070] Accordingly, by Fig.10 The geometric relationship is: , In the formula, is the incident wave velocity, is the reflected wave velocity, Represents the reflection angle.

[0071] because ,Right now , so: , In the formula, is the rate of change of the Mach wave size.

[0072] Depend on Fig.10 have to: , The Mach wave speed is : , It can be seen that for different incident wave velocities and detonation incident angle Mach reflection, Mach wave speed will have different values.

[0073] From equations (68) and (70), we can get the “three-wave point” growth angle: Or a trace, the slope satisfies the following relationship: , or , It can be seen from equations (68), (71), and (72) that like but: , like ,but: , Obviously, in the process of Mach wave development, the speed of the reflected wave and the Mach wave speed are greater than the speed of the detonation incident wave, and the growth angle of the "three wave points" is If the Mach wave reaches a stable state, the three speeds are equal. is equal to zero. From (72), we can get: , Substituting equation (75) into equation (70), we have , It can be seen from equations (75) and (76) that the velocities of the incident wave, reflected wave, and Mach wave along the “three wave point” trajectory are equal. Fig. 9 The geometric relationship in can be obtained: , , In the formula, and The cross section and The area of ​​the pipeline, and are the velocities of the incident detonation wave and the Mach wave, represents the Mach bar height.

[0074] Combining equation (77) and equation (78), we get: , Furthermore, based on the improved Whitham method and area function Solve for the Mach reflection pressure by the relationship between: , In the formula, , and are the pressures in the region after the Mach wave and the incident detonation wave, respectively. It represents the slow-varying coefficient, which is generally a constant and is usually obtained by fitting experimental data.

[0075] For the pressure in the Mach reflection (3) region The solution can be obtained according to formula (80). By combining formula (77), formula (78), and formula (80), and substituting them into formula (79), the Mach reflection pressure under different state equations can be calculated. However, it is worth noting that the slow-varying coefficient in the formula is an unknown quantity, which brings inconvenience to the theoretical calculation of Mach reflection detonation parameters. The theoretical calculations are derived.

[0076] According to Whitham's rules: , Assume that the shock wave passes through the cross section When the wave speed is , then integrating the above formula gives: , Similarly, , In the formula, is the detonation wave velocity, and are the moving speed of the medium behind the detonation wave front and the local sound speed, is the density of the detonation products.

[0077] Taking the natural logarithm of both sides of equation (80) and equation (83), we can obtain: , According to the definition of the speed of sound equation, we have: , According to the laws of conservation of mass and momentum, the pressure in the rear area of ​​the detonation wave front can be calculated: and the moving speed of the medium , taking the differentiation on both sides, we can get: , In the formula, .

[0078] Formula (86) can be solved to obtain , .

[0079] Further based on equations (85) and (86), we can get , , make ,but: , in, , Determine the area function relationship based on the law of conservation of mass and the law of conservation of momentum and energy. The equation of state and the Hugoniot relation can be used to calculate the pressure of the detonation wave array and the velocity of the medium behind the zone, as shown below: , according to The state equation and Hugoniot relation can be used to calculate the detonation wave pressure: , Using formula (84) and formula (85), we can get the following expression: , Furthermore, the pressure in the Mach reflection (3) region can be solved according to formula (80).

[0080] Further combining equation (90) and equation (92) we can obtain and Substituting the relationship into equations (84)-(89), , the slow-varying coefficient can be calculated ,because The value of changes slightly, take the average value.

[0081] Further, the slow-varying coefficient Substituting into equation (93), the Mach reflection pressure under different state equations can be calculated: , In general, for irregular oblique reflection (Mach reflection), the key is to solve the pressure in the (3) area after the Mach reflection. The following parameters need to be known in the solution process: the charge density of the explosive , dynamite State equation parameters , , , , , , , , the initial specific internal energy of the explosive , Specific volume of explosive CJ detonation products , , explosive detonation velocity .

[0082] The flow field parameters are determined in the following way: First, based on the improved Whitham method, the Mach reflection pressure formula (80) is derived from equations (66) to (79). The core problem in equation (80) is to solve the slow-varying coefficient , Formula (81)-Formula (92) is about how to solve the slow-varying coefficient The detailed solution process is as follows. Specifically, by combining equation (90) and equation (92), we can obtain and Substituting the relationship into equations (84)-(89), , the slow-varying coefficient can be calculated ,because The value of changes little, take the average value, and further change the slow coefficient Substituting into equation (93), we can calculate the Mach reflection pressure under different state equations: .

[0083] The three wave point trajectory is obtained by: a. Determine the coordinates of the intersection of the x-axis in the coordinate system based on the radius of the composite charge and the critical angle of Mach reflection, and use it as the coordinates of the initial trajectory point of the three-wave point trajectory; wherein, in the coordinate system, the origin is the detonation position, the x-axis represents the propagation distance of the detonation wave along the flow direction, and the y-axis represents the propagation distance of the detonation wave perpendicular to the flow direction.

[0084] Specifically, the coordinates of the initial trajectory points are expressed as ; in, , ; In the formula, represents the composite charge radius, represents the critical angle of Mach reflection.

[0085] It should be noted that the radius of the composite charge is the sum of the radii of the inner charge and the outer charge.

[0086] b. Based on the coordinates of the initial trajectory points, the detonation wave reflection pressure calculation model, the set step size and the number of trajectory points, the coordinates of each trajectory point are obtained in turn.

[0087] In specific implementation, the coordinates of the trajectory points are obtained by the following method: b1. Based on the coordinates of the current trajectory point, the current detonation wave incident angle is obtained, and then the current three-wave point growth angle is obtained.

[0088] Specifically, the three-wave point growth angle is expressed as: , in, ; In the formula, Indicates The three wave point growth angles corresponding to the coordinates of the trajectory points are: Indicates The detonation incident angle corresponding to the coordinates of the trajectory points is: Indicates that the detonation incident angle is The Mach reflection pressure at Indicates The coordinates of the trajectory points, Indicates the detonation wave pressure under the CJ state.

[0089] Specifically, the number of trajectory points is set according to actual needs.

[0090] b2. Based on the coordinates of the current trajectory point, the three-wave point growth angle and the set step size, the coordinates of the next trajectory point are obtained.

[0091] Specifically, the coordinates of the next trajectory point are expressed as ;in, , , In the formula, Indicates the set step size.

[0092] Preferably, the step size is set to 0.1.

[0093] c. Connect the coordinates of the initial trajectory point and the coordinates of each trajectory point to obtain the three-wave point trajectory of the detonation wave of the composite charge.

[0094] It should be noted that the (0) zone before the incident detonation wave TI and the Mach rod wave TS, the (1) zone before the reflected shock wave TR after the incident detonation wave TI, i.e., the detonation product zone, and the (2) zone between the reflected shock wave TR and the contact discontinuity TQ, i.e., the post-reflection shock wave state zone, the flow field parameters in each zone are the same as those solved in the regular oblique reflection process, and will not be repeated here.

[0095] Compared with the prior art, the present embodiment provides a method for constructing a model of the speed of a metal plate driven by a composite charge detonation, constructs the law of the motion characteristics of the metal plate at any time in the overpressure detonation of the composite charge, and can obtain the speed of the metal plate at any time. The driving law of the composite charge structure is described by the motion of the metal plate, and the work performance of the composite charge can be effectively evaluated. It can provide technical support for the in-depth study of the energy release rate of the composite charge and the structural optimization design, and can also provide technical support for the research and development of composite high-energy charge structure design technology, detonation wave superposition drive enhancement technology, and a new generation of directional killing warheads. Considering the interaction between the oblique shock wave and the rarefaction wave generated inside the composite charge during the detonation process, a theoretical calculation method for the internal flow field parameters of the composite charge is established. By partitioning and deriving the time-space relationship of physical parameters such as pressure acting on the internal detonation products of the composite charge with time, the internal parameters of the explosive after overpressure detonation can be accurately analyzed, and the theoretical closure of the interaction parameters of the detonation wave of the condensed explosive is achieved. Moreover, this method has wide applicability, high precision and strong stability. It can be used to characterize the theoretical calculation model of explosives under overpressure detonation, laying the foundation for studying the internal detonation reaction mechanism of composite charges, driving damage model and energy output response law.

[0096] Those skilled in the art will appreciate that all or part of the processes of the above-mentioned embodiments can be implemented by instructing related hardware through a computer program, and the program can be stored in a computer-readable storage medium, wherein the computer-readable storage medium is a disk, an optical disk, a read-only storage memory, or a random access memory, etc.

[0097] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for constructing a model of the velocity of a metal plate driven by a composite charge detonation, characterized in that: The following steps are involved: Determine each movement time period of the metal plate based on each detonation process stage and initial parameters of the composite charge during the detonation process of the composite charge; wherein the composite charge detonation time is taken as the initial time, and the initial parameters include the length of the composite charge, the diameters of the inner and outer layers of the charge, and the detonation velocities of the inner and outer layers of the charge; Based on the detonation process stage of each moving time period of the metal plate, the internal flow field parameters and detonation incident angle of the composite charge in each moving time period are obtained; Based on the internal flow field parameters of the composite charge in each movement time period, the initial parameters of the composite charge and the detonation incident angle, the velocity expression of the metal plate in each movement time period is obtained, and the model construction of the metal plate velocity is completed.

2. The method for constructing a model of the speed of a metal plate driven by composite charge detonation according to claim 1, characterized in that: The detonation process stages include regular oblique reflection process, irregular oblique reflection process and stable detonation propagation process; wherein, The movement time period of the metal plate corresponding to the regular oblique reflection process is ; The movement time period of the metal plate corresponding to the irregular oblique reflection process is ; The motion time period of the metal plate corresponding to the stable detonation propagation process is ; in, represents the moment of motion of the metal plate, It represents the motion moment of the metal plate when the detonation incident angle is the Mach critical angle, It represents the metal plate motion moment corresponding to when the composite charge detonation products enter into stable plane wave propagation.

3. The method for constructing a model of the speed of a metal plate driven by composite charge detonation according to claim 2, characterized in that: The metal plate motion moment corresponding to the detonation incident angle being the Mach critical angle It is expressed as: ， In the formula, , Respectively represent the diameters of the outer and inner layers of the composite charge, , They represent the detonation velocities of the outer and inner charges of the composite charge respectively.

4. The method for constructing a model of the speed of a metal plate driven by composite charge detonation according to claim 3, characterized in that: The metal plate movement moment corresponding to the composite charge detonation product entering the stable plane wave propagation It is expressed as: ， in, ， In the formula, Indicates the length of the composite charge.

5. The method for constructing a model of the speed of a metal plate driven by composite charge detonation according to claim 4, characterized in that: when When , the detonation incident angle satisfies the following formula: ， In the formula, Indicates at time The detonation incident angle at .

6. The method for constructing a model of the speed of a metal plate driven by composite charge detonation according to claim 2, characterized in that: When the metal plate moves for When the composite charge is in the detonation process stage, it is in the regular oblique reflection process, which includes the undetonated area of ​​the explosive, the detonation product area and the post-reflection shock wave state area. During this motion period, the metal plate moves at a speed of Movement, speed of the metal plate It is expressed as: ， In the formula, Indicates at time The detonation product pressure in the state area after the reflected shock wave is is the cross-sectional area of ​​the metal plate, Indicates the mass of the metal sheet.

7. The method for constructing a model of the speed of a metal plate driven by composite charge detonation according to claim 2, characterized in that: When the metal plate moves for The composite charge detonation process is in the irregular oblique reflection process, which includes the undetonated area of ​​explosives, the detonation product area, the post-reflection shock wave state area and the post-Mach wave state area. The speed of the metal plate in this motion period is It is expressed as: ， In the formula, represents the Mach wave velocity in the post-Mach wave state region, represents the speed of sound of the detonation products in the post-Mach wave state, Represents the dynamic rigidity index of the metal sheet material, represents the length of the post-Mach wave state region, represents the pressure of the detonation products in the post-Mach wave state region, represents the initial particle velocity of the Mach wave acting on the metal plate medium.

8. The method for constructing a model of the speed of a metal plate driven by composite charge detonation according to claim 4, characterized in that: The inner layer of the composite charge is aluminum explosive; when the metal plate moves for The composite charge detonation process is in a stable detonation propagation process. The metal plate speed in the metal plate movement period is It is expressed as: ， in, ， In the formula, Indicates the content of aluminum powder in the inner layer of aluminum-containing explosive in composite charge. represents the specific heat of gas at constant volume, represents the reaction rate of aluminum powder, represents the universal gas constant, It indicates the reaction heat of aluminum powder in the inner layer of aluminum explosive in the composite charge. represents the multi-party index, , represents the specific volume and density of the detonation products during the stable detonation propagation process, Indicates the mass of the metal sheet, is the cross-sectional area of ​​the metal plate, Represents the initial specific volume of the composite charge.

9. The method for constructing a model of the speed of a metal plate driven by composite charge detonation according to claim 6, characterized in that: The detonation product pressure in the state area after the reflected shock wave It is expressed as: ， In the formula, It represents the specific volume of the detonation products of explosives in the CJ state, Indicates the explosion pressure of explosives in CJ state, represents the velocity of the flow mass in the detonation product zone, , represent the density and specific volume of the detonation products in the state after the reflected shock wave, It represents the deflection angle of the flow mass in the state area after the reflected shock wave.

10. The method for constructing a model of the speed of a metal plate driven by composite charge detonation according to claim 7, characterized in that: The pressure of the detonation products in the post-Mach wave state region , obtained by the following formula: ， in, represents the slow-varying coefficient, represents the detonation incident angle.

Images