爆炸桶中冲击波超压测试方法研究

为准确测试含能破片在密闭容器中的爆炸冲击波超压,设计一种高效的压力测试方法。该方法采用粘土、硬橡胶垫、钢垫片来避免压力传感器与爆炸桶桶壁的硬接触,基本消除传统测试方法带来的桶壁振动噪声干扰。通过靶场实测结果表明:改进后的传感器测试结构可有效隔离振动噪声,大大减弱桶壁振动对传感器压力测试的影响,获得爆炸桶内壁上有效的含能破片冲击波超压压力数据,满足测试要求。     

基于FPGA和无线通信的冲击波超压采集系统设计

冲击波超压测试技术发展迅速.由于冲击波超压测试现场环境比较恶劣,为了提高测试系统的灵活性和可靠性,提出了一种基于FPGA和无线通信的冲击波超压采集系统的设计,从冲击波超压信号采集的发展现状出发,具体阐述了该系统总体方案的设计思路以及关键技术(电源管理优化设计、ZIGBEE模块和光纤模块等),同时分析了采用FPGA、无线...     

基于ICP压电传感器的冲击波超压存储测试系统设计

针对现有冲击波超压测试系统的不足,设计一款集传感器、调理电路及数据采集电路为一体的存储测试系统。采用存储测试技术原理设计的冲击波超压采集存储测试系统,利用新型ICP压电传感器能够将压电模块与内置电荷放大器集成一体的优势,使输出为放大信号;通过运算放大器和MAX4638的搭配运行,实现增益可调的功能;采用LC-Π型滤波对相应的模拟电压进行滤波处理,放大后的信号再经过Sallen-Key二阶滤波器进行滤波处理。采用FPGA进行数字逻辑控制设计,提高测试系统的稳定性和可靠性,并减小系统体积。经测试表明:在相同测试环境下,冲击波超压持续时间与测试半径成正比,而冲量大小与之成反比。系统已多次参与弹药静爆试验,验证其可靠性、稳定性。     

Shock wave overpressure due to metastable phase transformation in single component cryogens

A theory is presented which predicts the shock wave overpressure in a cryogenic explosion caused by heating the cryogen to the limit of thermodynamic metastability. It is determined that in a neighbourhood very close to the critical point the divergence of the bulk viscosity plays a very prominent role in the formation of a shock wave; and, in fact, is the necessary condition for its existence. A sample calculation is given for methane that yields an overpressure of the order of 500 lb in^?2.     

双层地下室空气冲击波特性的模型试验研究

高层建筑多层地下室内人防结构顶板核爆荷载的合理确定是目前人防结构设计中亟待解决的问题。文中在对实际工程的调查基础上，研究了双层地下室的试验模型，进行了空气冲击波在地下室模型内传播的爆炸试验，分析了作用在双层地下室底层结构顶板的爆炸压力分布特性，并得出多层地下室的底层顶板核爆荷载一般要小于单层地下室顶板核爆荷载设计值的结论．     

隧道内爆炸冲击波传播特性及爆炸荷载分布规律研究

隧道内爆炸产生复杂的爆炸冲击波流场,作用于隧道衬砌上的冲击波荷载分析十分困难.采用三维有限元计算方法,对带端墙隧道内爆炸空气冲击波的传播过程进行了数值模拟,给出了内爆炸产生的隧道内冲击波流场,并与双向开口隧道内爆炸流场进行了对比,分析了炸药装药形状、炸药引爆位置对爆炸荷载分布的影响,研究了作用于隧道衬砌上的反射冲击波荷载峰值分布规律,给出了估计衬砌上反射超压峰值的公式.     

Response of aluminium-infiltrated boron carbide cermets to shock wave loading

Shock-recovery and shock-spallation experiments were performed on two compositions of aluminium-infiltrated B₄C cermets as a function of shock pressure. Sixty-five per cent volume B₄C-Al cermets were recovered largely intact after shock loading up to pressures of ca. 12 GPa which permitted a critical study of the microstructural changes produced by the shock. Significantly, shock loading to between 12 and 13 GPa produced a combination of dislocation debris, stacking faults and deformation twins in a small fraction of the B₄C grains. Fragmentation of shock-loaded 80% B₄C-Al samples prevented meaningful microstructural investigation. Spall-strength testing also provided indirect evidence for the Hugoniot elastic limits (HEL) of these composites. Spall-strength calculations based on an elastic equation of state for 65% B₄C-Al indicated that the elastic regime extended up to shock pressures of ca. 10 GPa, or approximately 65% of the HEL of polycrystalline B₄C. A complete loss of spall strength was then observed at the transition to a plastic equation of state at a pressure of 12 GPa which coincided with observations of plasticity within the B₄C-substructure. This study demonstrated that composites containing a highly ductile phase combined with a high compressive strength ceramic phase could support high dynamic tensile stresses by resisting the propagation of catastrophic cracks through the brittle ceramic substructure.     

碎石机的聚焦冲击波研究和测量

一个椭球反射体的第一焦点水下火花放电产生球面波可以聚焦在第二焦点,产生的脉冲压力可达１００×１０６Ｐａ,本文指出了不同反射体的形状、尺寸和材料对聚焦效果、脉冲形状和焦斑的影响。为了定量研究水下聚焦冲击波,我们研制了一种特殊的冲击波压力传感器（探头）,用这种探头已对国内大部分厂家的碎石机进行电声性能的测试,效果很好。     

On the structure of an inviscid shock wave

Summary The structure of one-dimensional shock waves is investigated using the Navier-Stokes equations for the gas phase. The resulting system of three ordinary nonlinear differential equations is reduced to a system of two autonomous nonlinear differential equations which are solved exactly. This solution is obtained formally by assuming that the heat conductivity is temperature dependent, and that the viscosity is neglected. A deduction of the behaviour of entropy across inviscid shock waves is also given.