To quickly break through a reinforced concrete wall and meet the damage range requirements of rescuers entering the building,the combined damage characteristics of the reinforced concrete wall caused by EFP penetratio...To quickly break through a reinforced concrete wall and meet the damage range requirements of rescuers entering the building,the combined damage characteristics of the reinforced concrete wall caused by EFP penetration and explosion shock wave were studied.Based on LS-DYNA finite element software and RHT model with modified parameters,a 3D large-scale numerical model was established for simulation analysis,and the rationality of the material model parameters and numerical simulation algorithm were verified.On this basis,the combined damage effect of EFP penetration and explosion shock wave on reinforced concrete wall was studied,the effect of steel bars on the penetration of EFP was highlighted,and the effect of impact positions on the damage of the reinforced concrete wall was also examined.The results reveal that the designed shaped charge can form a crater with a large diameter and high depth on the reinforced concrete wall.The average crater diameter is greater than 67 cm(5.58 times of charge diameter),and crater depth is greater than 22 cm(1.83 times of charge diameter).The failure of the reinforced concrete wall is mainly caused by EFP penetration.When only EFP penetration is considered,the average diameter and depth of the crater are 54.0 cm(4.50 times of charge diameter)and 23.7 cm(1.98 times of charge diameter),respectively.The effect of explosion shock wave on crater depth is not significant,resulting in a slight increase in crater depth.The average crater depth is 24.5 cm(2.04 times of charge diameter)when the explosion shock wave is considered.The effect of explosion shock wave on the crater diameter is obvious,which can aggravate the damage range of the crater,and the effect gradually decreases with the increase of standoff distance.Compared with the results for a plain concrete wall,the crater diameter and crater depth of the reinforced concrete wall are reduced by 5.94%and 9.96%,respectively.Compared to the case in which the steel bar is not hit,when the EFP hit one steel bar and the intersection of two steel bars,the crater diameter decreases by 1.36%and 5.45%respectively,the crater depth decreases by 4.92%and 14.02%respectively.The EFP will be split by steel bar during the penetration process,resulting in an irregular trajectory.展开更多
为综合分析爆炸成型弹丸(explosively formed projectile,EFP)的构型对其气动特性和侵彻性能的影响,实现兼具良好气动特性和侵彻性能的EFP设计。开展了EFP的成型和飞行试验,在试验验证数值有效性的基础上,基于任意拉格朗日欧拉(arbitrar...为综合分析爆炸成型弹丸(explosively formed projectile,EFP)的构型对其气动特性和侵彻性能的影响,实现兼具良好气动特性和侵彻性能的EFP设计。开展了EFP的成型和飞行试验,在试验验证数值有效性的基础上,基于任意拉格朗日欧拉(arbitrary Lagrange-Euler,ALE)算法分析了后翻型EFP的三种典型构型(实心杆状、小空腔状、大空腔状)的成型过程及气动特性,并进一步开展了三种构型EFP侵彻半无限厚45#钢的数值模拟。结果表明:EFP小空腔结构提高了其飞行稳定性;空腔的增大降低了EFP的存速能力,实心、小空腔、大空腔三种构型的EFP炸高在1000倍弹径(30 m)时平均速度降分别为158 m/s,172 m/s,210 m/s;随着EFP空腔的增大,靶板开坑形貌由漏斗状逐渐转为等直径状。从工程实践角度设计EFP构型时:对于近距离目标应选取实心型;对于远距离目标应选取小空腔型。展开更多
为达成快速精准预测爆炸成型弹丸(explosively formed projectile,EFP)速度以及检验校准JWL状态方程参数等目的,使用LS-DYNA有限元软件建立Φ65 mm EFP的数值模型,研究JWL状态方程各参数对EFP速度的影响规律。在此基础上,拟合建立基于JW...为达成快速精准预测爆炸成型弹丸(explosively formed projectile,EFP)速度以及检验校准JWL状态方程参数等目的,使用LS-DYNA有限元软件建立Φ65 mm EFP的数值模型,研究JWL状态方程各参数对EFP速度的影响规律。在此基础上,拟合建立基于JWL状态方程参数的EFP速度计算公式,构建EFP速度的BP神经网络预测模型,生成学习样本对网络模型进行训练。结果表明,JWL状态方程参数对EFP速度存在显著影响,参数R_(1)影响最大,各参数影响的大小顺序为R_(1)、A、B、R_(2)、E_(0)、ω;计算公式和网络模型均能够精准预测EFP速度,网络模型的预测精度优于计算公式,其中计算公式的结果误差绝大部分能够控制在10%以内,网络模型的预测误差均不超过5%。展开更多
为改进整体式多爆炸成型弹丸(Multiple Explosively Formed Projectile,MEFP)战斗部中位于边缘位置处的药型罩口部闭合较差的问题,设计一种沿周向壁厚不同的偏心药型罩。将该药型罩应用于D型装药结构战斗部中,通过理论分析以及数值仿真...为改进整体式多爆炸成型弹丸(Multiple Explosively Formed Projectile,MEFP)战斗部中位于边缘位置处的药型罩口部闭合较差的问题,设计一种沿周向壁厚不同的偏心药型罩。将该药型罩应用于D型装药结构战斗部中,通过理论分析以及数值仿真方法,针对药型罩较厚一侧朝向和偏心距大小对药型罩成型的影响规律进行研究,开展爆炸成型弹丸(Explosively Formed Projectile,EFP)软回收试验。研究结果表明:偏心药型罩较厚侧朝向及偏心距大小对EFP各方向速度基本无影响,对EFP成型效果影响较大;药型罩较厚侧朝向战斗部中心时成型效果最佳;偏心距的大小能够调整药型罩周围微元向中心压合的速度差,改善药型罩口部包合情况;试验中回收到的EFP成型结果与仿真结果吻合度较高;偏心药型罩通过调整药型罩壁厚与爆轰波强度的匹配关系能够改善非对称爆轰下EFP的成型,有效解决D型装药结构MEFP战斗部位于边缘位置处药型罩成型较差的问题,为整体式MEFP战斗部边缘位置处药型罩结构设计提供参考。展开更多
针对同一成型装药形成多模毁伤元问题,利用LS-DYNA程序,研究了单点起爆位置对爆炸成型侵彻体(explosively formed penetrator,EFP)成型的影响规律。当起爆点距离药型罩的轴向距离从0倍装药口径增加到0.72倍装药口径,EFP速度提高了37.8%...针对同一成型装药形成多模毁伤元问题,利用LS-DYNA程序,研究了单点起爆位置对爆炸成型侵彻体(explosively formed penetrator,EFP)成型的影响规律。当起爆点距离药型罩的轴向距离从0倍装药口径增加到0.72倍装药口径,EFP速度提高了37.8%,长径比增加了1倍多;优化设计成型装药结构,分析了主装药端面中心点起爆和药型罩顶点起爆爆轰波传播规律,实现了杆式EFP、EFP 2种模态的转换。通过X光成像实验进行了验证,实验结果与数值模拟结果吻合较好。展开更多
基金supported by the Scientific and Technological Innovation Project(Grant No.KYGYZB0019003)。
文摘To quickly break through a reinforced concrete wall and meet the damage range requirements of rescuers entering the building,the combined damage characteristics of the reinforced concrete wall caused by EFP penetration and explosion shock wave were studied.Based on LS-DYNA finite element software and RHT model with modified parameters,a 3D large-scale numerical model was established for simulation analysis,and the rationality of the material model parameters and numerical simulation algorithm were verified.On this basis,the combined damage effect of EFP penetration and explosion shock wave on reinforced concrete wall was studied,the effect of steel bars on the penetration of EFP was highlighted,and the effect of impact positions on the damage of the reinforced concrete wall was also examined.The results reveal that the designed shaped charge can form a crater with a large diameter and high depth on the reinforced concrete wall.The average crater diameter is greater than 67 cm(5.58 times of charge diameter),and crater depth is greater than 22 cm(1.83 times of charge diameter).The failure of the reinforced concrete wall is mainly caused by EFP penetration.When only EFP penetration is considered,the average diameter and depth of the crater are 54.0 cm(4.50 times of charge diameter)and 23.7 cm(1.98 times of charge diameter),respectively.The effect of explosion shock wave on crater depth is not significant,resulting in a slight increase in crater depth.The average crater depth is 24.5 cm(2.04 times of charge diameter)when the explosion shock wave is considered.The effect of explosion shock wave on the crater diameter is obvious,which can aggravate the damage range of the crater,and the effect gradually decreases with the increase of standoff distance.Compared with the results for a plain concrete wall,the crater diameter and crater depth of the reinforced concrete wall are reduced by 5.94%and 9.96%,respectively.Compared to the case in which the steel bar is not hit,when the EFP hit one steel bar and the intersection of two steel bars,the crater diameter decreases by 1.36%and 5.45%respectively,the crater depth decreases by 4.92%and 14.02%respectively.The EFP will be split by steel bar during the penetration process,resulting in an irregular trajectory.
文摘为达成快速精准预测爆炸成型弹丸(explosively formed projectile,EFP)速度以及检验校准JWL状态方程参数等目的,使用LS-DYNA有限元软件建立Φ65 mm EFP的数值模型,研究JWL状态方程各参数对EFP速度的影响规律。在此基础上,拟合建立基于JWL状态方程参数的EFP速度计算公式,构建EFP速度的BP神经网络预测模型,生成学习样本对网络模型进行训练。结果表明,JWL状态方程参数对EFP速度存在显著影响,参数R_(1)影响最大,各参数影响的大小顺序为R_(1)、A、B、R_(2)、E_(0)、ω;计算公式和网络模型均能够精准预测EFP速度,网络模型的预测精度优于计算公式,其中计算公式的结果误差绝大部分能够控制在10%以内,网络模型的预测误差均不超过5%。
文摘为改进整体式多爆炸成型弹丸(Multiple Explosively Formed Projectile,MEFP)战斗部中位于边缘位置处的药型罩口部闭合较差的问题,设计一种沿周向壁厚不同的偏心药型罩。将该药型罩应用于D型装药结构战斗部中,通过理论分析以及数值仿真方法,针对药型罩较厚一侧朝向和偏心距大小对药型罩成型的影响规律进行研究,开展爆炸成型弹丸(Explosively Formed Projectile,EFP)软回收试验。研究结果表明:偏心药型罩较厚侧朝向及偏心距大小对EFP各方向速度基本无影响,对EFP成型效果影响较大;药型罩较厚侧朝向战斗部中心时成型效果最佳;偏心距的大小能够调整药型罩周围微元向中心压合的速度差,改善药型罩口部包合情况;试验中回收到的EFP成型结果与仿真结果吻合度较高;偏心药型罩通过调整药型罩壁厚与爆轰波强度的匹配关系能够改善非对称爆轰下EFP的成型,有效解决D型装药结构MEFP战斗部位于边缘位置处药型罩成型较差的问题,为整体式MEFP战斗部边缘位置处药型罩结构设计提供参考。
文摘针对同一成型装药形成多模毁伤元问题,利用LS-DYNA程序,研究了单点起爆位置对爆炸成型侵彻体(explosively formed penetrator,EFP)成型的影响规律。当起爆点距离药型罩的轴向距离从0倍装药口径增加到0.72倍装药口径,EFP速度提高了37.8%,长径比增加了1倍多;优化设计成型装药结构,分析了主装药端面中心点起爆和药型罩顶点起爆爆轰波传播规律,实现了杆式EFP、EFP 2种模态的转换。通过X光成像实验进行了验证,实验结果与数值模拟结果吻合较好。
