The double casing warhead with sandwiched charge is a novel fragmentation warhead that can produce two groups of fragments with different velocity,and the previous work has presented a calculation formula to determine...The double casing warhead with sandwiched charge is a novel fragmentation warhead that can produce two groups of fragments with different velocity,and the previous work has presented a calculation formula to determine the maximum fragment velocity.The current work builds on the published formula to further develop a formula for calculating the axial distribution characteristics of the fragment velocity.For this type of warhead,the simulation of the dispersion characteristics of the detonation products at different positions shows that the detonation products at the ends have a much larger axial velocity than those in the middle,and the detonation products have a greater axial dispersion velocity when they are closer to the central axis.The loading process and the fragment velocity vary with the axial position for both casing layers,and the total velocity of the fragments is the vector sum of the radial velocity and the axial velocity.At the same axial position,the acceleration time of the inner casing is greater than that of the outer casing.For the same casing,the fragments generated at the ends have a longer acceleration time than the fragments from the middle.The proposed formula is validated with the X-ray radiography results of the four warheads previously tested experimentally and the 3D smoothedparticle hydrodynamics numerical simulation results of several series of new warheads with different configurations.The formula can accurately and reliably calculate the fragment velocity when the lengthto-diameter ratio of the charge is greater than 1.5 and the thickness of the casing is less than 20%its inner radius.This work thus provides a key reference for the theoretical analysis and the design of warheads with multiple casings.展开更多
在当今军事技术的快速发展中,高速自锐侵彻战斗部在毁伤深埋高价值硬目标与多层建筑时,具有巨大的战略价值;文章通过建立动力学响应和磁场分析模型,深入研究自锐战斗部侵彻6 m C40混凝土靶板和多层钢筋混凝土靶板时引信的力学与磁场响...在当今军事技术的快速发展中,高速自锐侵彻战斗部在毁伤深埋高价值硬目标与多层建筑时,具有巨大的战略价值;文章通过建立动力学响应和磁场分析模型,深入研究自锐战斗部侵彻6 m C40混凝土靶板和多层钢筋混凝土靶板时引信的力学与磁场响应特性,为提高侵彻自锐战斗部毁伤精度提供支撑;在引信动力学响应的研究中,战斗部侵彻混凝土靶板历程,侵蚀后的靶板呈现出漏斗形状,随着战斗部侵彻的深入,应力波的稀疏效应逐渐减弱,战斗部的速度线性衰减,并在最终进入稳定侵彻模式的过程中,速度下降约52%;由于应力波在战斗部内部的传递与叠加导致引信位置检测的过载信号较为震荡;在引信磁场分析的研究中,地磁倾角为90°、地磁偏角为0°(即地磁场垂直于靶板中心线)时,X、Y轴磁通密度幅值小、信号无规律、穿层特征不明显;Z轴磁通密度幅值大、信号规则、穿层特征明显;地磁场强度越大,钢筋半径越大,地磁倾角越大,侵彻靶板层信号特征越明显。而Z轴磁通密度不受地磁偏角影响。展开更多
In order to study the impacts of warhead geometry and initiation pattern on the lethality of aimable warhead,multi-point synchronous initiated hexagonal prism and cylindrical warheads were compared through numerical s...In order to study the impacts of warhead geometry and initiation pattern on the lethality of aimable warhead,multi-point synchronous initiated hexagonal prism and cylindrical warheads were compared through numerical simulation,combined with theoretical formulas of fragment deceleration and target plugging.Enhancements of fragment velocity,kinetic energy and density toward the target and target destructions were analyzed.The results show that hexagonal prism warhead can produce dense fragment beams and enhance average velocity and kinetic energy with asymmetric eight-point initiation by 24.13% and54.52%respectively,which are higher than those of the isometric or same weight cylindrical warhead.The effective fragments are still relatively concentrated in an area of 8m×2mfor the hexagonal prism warhead when the distance between warhead and target is 40m.展开更多
The lethality of a semi-preformed fragment warhead is closely related to the expand velocity and spatial distribution of the fragments from ruptured metal casing. The topic of how to improve the utilization of charge ...The lethality of a semi-preformed fragment warhead is closely related to the expand velocity and spatial distribution of the fragments from ruptured metal casing. The topic of how to improve the utilization of charge of have been drawing great attention from researchers and designer in this filed. In present paper,in order to investigate the influence of charge initiation manners on the scattering characteristics of semi-preformed fragment warhead, the numerical simulations and experimental test are conducted.Firstly, the influence of grid density on numerical results is investigated, and a proper numerical model with relatively high accuracy and effectiveness is determined. Then. numerical simulations of three kinds of different initiation position of a semi-preformed fragment warhead are carried out. An experimental test of the explosion of a semi-preformed fragment warhead is carried out. By comparing and analyzing the numerical results and experimental data, it is found that the initiation manners have great influence on scattering characteristics of semi-preformed fragment warhead. The researcher work of this paper would provide an effective alternative method to optimize the design of warhead.展开更多
New advanced numerical computer model enabling accurate simulation of fragmentation parameters of large Length over Diameter(L/D)explosively driven metal shells has been developed and validated.The newly developed lar...New advanced numerical computer model enabling accurate simulation of fragmentation parameters of large Length over Diameter(L/D)explosively driven metal shells has been developed and validated.The newly developed large L/D multi-region model links three-dimensional axisymmetric high strain high strain-rate hydrocode analyses with the conventional set of Picatinny Arsenal FRAGmentation(PAFRAG)simulation routines.The standard PAFRAG modeling technique is based on the Mott's theory of break-up of idealized cylindrical"ring-bombs",in which the length of the average fragment is a function of the radius and velocity of the shell at the moment of break-up,and the mechanical properties of the metal.In the newly developed multi-region model,each of the shell region,the break-up is assumed to occur instantaneously,whereas the entire shell is modeled to fragment at multiple times,according to the number of the regions considered.According to PAFRAG methodology,the required input for both the natural and the controlled fragmentation models including the geometry and the velocity of the shell at moment of break-up had been provided from the hydrocode analyses and validated with available experimental data.The newly developed large L/D multi-region PAFRAG model has been shown to accurately reproduce available experimental fragmentation data.展开更多
A projectile system is proposed to improve efficiency and effectiveness of damage done by anti-tank weapon system on its target by designing a ballistic projectile that can split into multiple warheads and engage a ta...A projectile system is proposed to improve efficiency and effectiveness of damage done by anti-tank weapon system on its target by designing a ballistic projectile that can split into multiple warheads and engage a target at the same time. This idea has been developed in interest of saving time consumed from the process of reloading and additional number of rounds wasted on target during an attack. The proposed system is achieved in three steps: Firstly, a mathematical model is prepared using the basic equations of motion. Second, An Ejection Mechanism of proposed warhead is explained with the help of schematics. Third, a part of numerical simulation which is done using the MATLAB software. The final result shows various ranges and times when split can be effectively achieved. With the new system,impact points are increased and hence it has a better probability of hitting a target.展开更多
For the characterization of the behaviors of a metal material in events like expanding warheads, it is necessary to know its strength and ductility at high strain rates, around 104e105/s. The flyer plate impact testin...For the characterization of the behaviors of a metal material in events like expanding warheads, it is necessary to know its strength and ductility at high strain rates, around 104e105/s. The flyer plate impact testing produces the uniform stress and strain rates but the testing is expensive. The Taylor test is relatively inexpensive but produces non-uniform stress and strain fields, and the results are not so easily inferred for material modeling. In the split-Hopkinson bar(SHB), which may be used in compression, tension and torsion testing, the strain rates never exceeds 103/s. In the present work, we use the expanding ring test where the strain rate is 104e105/s. A streak camera is used to examine the expanding ring velocity, and a water tank is used to collect the fragments. The experimental results are compared with the numerical simulations using the hydrocodes AUTODYN, IMPETUS Afea and a regularized smooth particle(RSPH) software. The number of fragments increases with the increase in the expansion velocity of the rings. The number of fragments is similar to the experimental results. The RSPH software shows much the same results as the AUTODYN where the Lagrangian solver is used for the ring. The IMPETUS Afea solver shows a somewhat different fragmentation characteristic due to the node splitting algorithm that induces pronounced tensile splitting.展开更多
A novel simulation method for fuze warhead system(FWS) at very low altitude flight is proposed to solve adaptability issues of the traditional one in the naval battle. Firstly, a simulation system framework is present...A novel simulation method for fuze warhead system(FWS) at very low altitude flight is proposed to solve adaptability issues of the traditional one in the naval battle. Firstly, a simulation system framework is presented. Then the detailed implementation of a novel general fuze model, a novel sea echo model and a novel warhead dynamic effectiveness power field algorithm including the simulation system are presented. Finally, simulation results show good performance of the proposed method. The proposed method can simulate the echo signal when the complex fuze antennas detect target and the sea at the same time, and can truly reflect the target positions hit by the warhead fragments. The proposed method can solve the existing problems in the FWS simulation system.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.11872121)。
文摘The double casing warhead with sandwiched charge is a novel fragmentation warhead that can produce two groups of fragments with different velocity,and the previous work has presented a calculation formula to determine the maximum fragment velocity.The current work builds on the published formula to further develop a formula for calculating the axial distribution characteristics of the fragment velocity.For this type of warhead,the simulation of the dispersion characteristics of the detonation products at different positions shows that the detonation products at the ends have a much larger axial velocity than those in the middle,and the detonation products have a greater axial dispersion velocity when they are closer to the central axis.The loading process and the fragment velocity vary with the axial position for both casing layers,and the total velocity of the fragments is the vector sum of the radial velocity and the axial velocity.At the same axial position,the acceleration time of the inner casing is greater than that of the outer casing.For the same casing,the fragments generated at the ends have a longer acceleration time than the fragments from the middle.The proposed formula is validated with the X-ray radiography results of the four warheads previously tested experimentally and the 3D smoothedparticle hydrodynamics numerical simulation results of several series of new warheads with different configurations.The formula can accurately and reliably calculate the fragment velocity when the lengthto-diameter ratio of the charge is greater than 1.5 and the thickness of the casing is less than 20%its inner radius.This work thus provides a key reference for the theoretical analysis and the design of warheads with multiple casings.
文摘在当今军事技术的快速发展中,高速自锐侵彻战斗部在毁伤深埋高价值硬目标与多层建筑时,具有巨大的战略价值;文章通过建立动力学响应和磁场分析模型,深入研究自锐战斗部侵彻6 m C40混凝土靶板和多层钢筋混凝土靶板时引信的力学与磁场响应特性,为提高侵彻自锐战斗部毁伤精度提供支撑;在引信动力学响应的研究中,战斗部侵彻混凝土靶板历程,侵蚀后的靶板呈现出漏斗形状,随着战斗部侵彻的深入,应力波的稀疏效应逐渐减弱,战斗部的速度线性衰减,并在最终进入稳定侵彻模式的过程中,速度下降约52%;由于应力波在战斗部内部的传递与叠加导致引信位置检测的过载信号较为震荡;在引信磁场分析的研究中,地磁倾角为90°、地磁偏角为0°(即地磁场垂直于靶板中心线)时,X、Y轴磁通密度幅值小、信号无规律、穿层特征不明显;Z轴磁通密度幅值大、信号规则、穿层特征明显;地磁场强度越大,钢筋半径越大,地磁倾角越大,侵彻靶板层信号特征越明显。而Z轴磁通密度不受地磁偏角影响。
文摘In order to study the impacts of warhead geometry and initiation pattern on the lethality of aimable warhead,multi-point synchronous initiated hexagonal prism and cylindrical warheads were compared through numerical simulation,combined with theoretical formulas of fragment deceleration and target plugging.Enhancements of fragment velocity,kinetic energy and density toward the target and target destructions were analyzed.The results show that hexagonal prism warhead can produce dense fragment beams and enhance average velocity and kinetic energy with asymmetric eight-point initiation by 24.13% and54.52%respectively,which are higher than those of the isometric or same weight cylindrical warhead.The effective fragments are still relatively concentrated in an area of 8m×2mfor the hexagonal prism warhead when the distance between warhead and target is 40m.
基金supported by the Joint Foundation project for Young Scientists of Ministry of Education(6141A02033108)National Natural Science Foundation of China(11502180)
文摘The lethality of a semi-preformed fragment warhead is closely related to the expand velocity and spatial distribution of the fragments from ruptured metal casing. The topic of how to improve the utilization of charge of have been drawing great attention from researchers and designer in this filed. In present paper,in order to investigate the influence of charge initiation manners on the scattering characteristics of semi-preformed fragment warhead, the numerical simulations and experimental test are conducted.Firstly, the influence of grid density on numerical results is investigated, and a proper numerical model with relatively high accuracy and effectiveness is determined. Then. numerical simulations of three kinds of different initiation position of a semi-preformed fragment warhead are carried out. An experimental test of the explosion of a semi-preformed fragment warhead is carried out. By comparing and analyzing the numerical results and experimental data, it is found that the initiation manners have great influence on scattering characteristics of semi-preformed fragment warhead. The researcher work of this paper would provide an effective alternative method to optimize the design of warhead.
文摘New advanced numerical computer model enabling accurate simulation of fragmentation parameters of large Length over Diameter(L/D)explosively driven metal shells has been developed and validated.The newly developed large L/D multi-region model links three-dimensional axisymmetric high strain high strain-rate hydrocode analyses with the conventional set of Picatinny Arsenal FRAGmentation(PAFRAG)simulation routines.The standard PAFRAG modeling technique is based on the Mott's theory of break-up of idealized cylindrical"ring-bombs",in which the length of the average fragment is a function of the radius and velocity of the shell at the moment of break-up,and the mechanical properties of the metal.In the newly developed multi-region model,each of the shell region,the break-up is assumed to occur instantaneously,whereas the entire shell is modeled to fragment at multiple times,according to the number of the regions considered.According to PAFRAG methodology,the required input for both the natural and the controlled fragmentation models including the geometry and the velocity of the shell at moment of break-up had been provided from the hydrocode analyses and validated with available experimental data.The newly developed large L/D multi-region PAFRAG model has been shown to accurately reproduce available experimental fragmentation data.
文摘A projectile system is proposed to improve efficiency and effectiveness of damage done by anti-tank weapon system on its target by designing a ballistic projectile that can split into multiple warheads and engage a target at the same time. This idea has been developed in interest of saving time consumed from the process of reloading and additional number of rounds wasted on target during an attack. The proposed system is achieved in three steps: Firstly, a mathematical model is prepared using the basic equations of motion. Second, An Ejection Mechanism of proposed warhead is explained with the help of schematics. Third, a part of numerical simulation which is done using the MATLAB software. The final result shows various ranges and times when split can be effectively achieved. With the new system,impact points are increased and hence it has a better probability of hitting a target.
文摘For the characterization of the behaviors of a metal material in events like expanding warheads, it is necessary to know its strength and ductility at high strain rates, around 104e105/s. The flyer plate impact testing produces the uniform stress and strain rates but the testing is expensive. The Taylor test is relatively inexpensive but produces non-uniform stress and strain fields, and the results are not so easily inferred for material modeling. In the split-Hopkinson bar(SHB), which may be used in compression, tension and torsion testing, the strain rates never exceeds 103/s. In the present work, we use the expanding ring test where the strain rate is 104e105/s. A streak camera is used to examine the expanding ring velocity, and a water tank is used to collect the fragments. The experimental results are compared with the numerical simulations using the hydrocodes AUTODYN, IMPETUS Afea and a regularized smooth particle(RSPH) software. The number of fragments increases with the increase in the expansion velocity of the rings. The number of fragments is similar to the experimental results. The RSPH software shows much the same results as the AUTODYN where the Lagrangian solver is used for the ring. The IMPETUS Afea solver shows a somewhat different fragmentation characteristic due to the node splitting algorithm that induces pronounced tensile splitting.
文摘A novel simulation method for fuze warhead system(FWS) at very low altitude flight is proposed to solve adaptability issues of the traditional one in the naval battle. Firstly, a simulation system framework is presented. Then the detailed implementation of a novel general fuze model, a novel sea echo model and a novel warhead dynamic effectiveness power field algorithm including the simulation system are presented. Finally, simulation results show good performance of the proposed method. The proposed method can simulate the echo signal when the complex fuze antennas detect target and the sea at the same time, and can truly reflect the target positions hit by the warhead fragments. The proposed method can solve the existing problems in the FWS simulation system.