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The formation mechanism of an EFP(explosively formed projectile) using a double curvature liner under the overpressure effect generated by a regular oblique reflection was investigated in this paper.Based on the detonation wave propagation theory,the change of the incident angle of the detonation wave collision at different positions and the distribution area of the overpressure on the surface of the liner were calculated.Three-dimensional numerical simulations of the formation process of the EFP with tail as well as the ability to penetrate 45# steel were performed using LS-DYNA software,and the EFP ve-locity,the penetration ability,and the forming were assessed via experiments and x-ray photographs.The experimental results coincides with those of the simulations.Results indicate that the collision of the detonation wave was controlled to be a regular oblique reflection acting on the liner by setting the di-mensions of the unit charge and maintaining the pressure at the collision point region at more than 2.4 times the CJ detonation when the incident angle approached the critical angle.The distance from the liner midline to the boundary of the area within which the pressure ratio of the regular oblique reflection pressure to the CJ detonation pressure was greater than 2.5,2,and 1.5was approximately 0.66 mm,1.32 mm,and 3.3 mm,respectively.It is noted that pressure gradient caused the liner to turn inside out in the middle to form the head of the EFP and close the two tails of the EFP at approximately 120μs.The penetration depth of the EFP into a 45# steel target exceeded 30 mm,and there was radial expansion between the head and tail of the EFE increasing the penetration resistance of the EFP.Therefore,the structural size of the unit charge and the liner can be further optimized to reduce resistance to increase the penetration ability of the EFP. 相似文献
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为了进一步在教学中实施心理健康教育及心理干预,笔者对武警学院2003级学员的心理健康状况进行了调查。结果发现,武警学院学员在人际关系、偏执和精神病性因子上显著低于军队常模,在躯体化、焦虑、精神病性因子上显著高于地方常模,人际关系、抑郁、敌对因子上显著低于地方常模。分析研究学员心理健康状况,对于学员的健康成长具有重要意义。 相似文献
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船舶在海水中产生的电场是一种重要的目标特性,一般可用水平直流电偶极子的场进行模拟.基于空气-海水两层模型的假设条件,提出了一种海水中水平直流电偶极子源定位方法.该方法利用水平直流电偶极子的水下电场分布特征,通过在垂直海面方向布置两个三轴电场传感器测得相应位置的电场强度,就能反演估计出偶极子在水平面内相对于测量点的位置.... 相似文献
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基于VPDN的污染源自动监控系统研究 总被引:4,自引:0,他引:4
建立污染源自动监控系统是环境监测的重要举措。阐述了VPDN技术及其优点,重点论述了基于VPDN的污染源自动监控系统,包括系统的基本思想、结构及功能和如何实现的问题。通过实际运行表明该系统运行稳定、操作方便,易于达到远程监控、实时报警、远程管理和长周期稳定运行的要求。 相似文献
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以高超声速飞行器为研究对象,针对俯冲段精确制导及机动突防问题,基于反馈线性化与滑模控制研究了机动突防滑模跟踪制导方法。首先设计纵向俯冲及侧向机动弹道,其次利用反馈线性化将非线性运动方程转化为线性方程,基于该线性方程利用滑模控制对已设计的弹道进行跟踪,最终将线性跟踪制导律转换到非线性系统中获得非线性滑模跟踪制导律,该制导律完全基于飞行器当前运动状态,所需的相对运动信息大大减少。CAV-H飞行器制导实例仿真表明,该方法能够实现俯冲段精确制导及机动飞行,且对初始及过程偏差具有较强的鲁棒性,能够为高超声速飞行器俯冲段制导提供有益参考。 相似文献