低压长脉冲作用下PBX炸药的响应特性

为研究塑料粘接炸药(PBX炸药)在低压长脉冲作用下的响应特性,采用大落锤试验的方法对壳体约束下的炸药样品进行低速撞击加载; 采用薄膜式PVDF对炸药试样顶部和底部的压力-时间曲线进行测量,通过壳体外表面的应变片测试壳体的环向和轴向应变,同时采用高速相机捕捉炸药在撞击作用下的反应发光现象; 采用LS-DYNA非线性有限元软件开展数值模拟,研究大落锤冲击载荷作用下PBX炸药的动态响应特性。结果表明,落锤撞击速度为3 m/s时,炸药受撞击面的峰值压力约为100 MPa,炸药不发生反应; 落锤撞击速度为5 m/s时,炸药受撞击面的峰值压力为200 MPa,炸药发生明显的化学反应; 有限元计算结果与试验测试结果具有较高的吻合度,可以很好地模拟炸药在低压长脉冲冲击下的力学响应特性。

Response Characteristics of PBX Explosives Under theShock Waves of Low Pressure and Long-pluse

In order to study the reponse characteristics of PBX explosives under low pressure and long pulse conditions,the low-velocity impact loading of erplosive samples restricted by case was carried out by the drop hammer test. The pressure-time curve of top and bottom of PBX explosives was measured by using PVDF gauges,and the hoop strain and axial strain were captured by using strain foil. The high-speed camera was utilized to determine whether chemical reaction occurring inside PBX explosives under impact. The changing process of internal pressure of PBX explosives under the drop-test shock loading was stimulated by applying LS-DYNA nonlinear finite element software. Under the condition of impact velocity of 3 m/s,the peak pressure on the top surface of PBX explosives is almost 100 MPa,and there is no chemical reaction. Under the condition of impact velocity of 5 m/s,the peak pressure on the top surface of PBX explosives is almost 200 MPa,and the obvious chemical reaction is observed during impact process. The computing results are well agreed with the test results,so the dynamic response properties of the explosives under the conditions of the low pressure and long-pluse can be stimulated very well.