慢烤过程中热应力对HMX基含铝炸药装药响应特性的影响

Effect of Thermal Stress on the Response Characteristics of HMX Based Aluminized Explosive Charge in Slow Cook-off Test

为获得炸药装药在慢烤过程中热应力的变化规律,设计了一套热应力测试装置,获得了奥克托今(HMX)基含铝炸药装药在密闭约束条件下热应力随温度的变化曲线;通过调整烤燃弹内惰性包覆层与装药的体积比,改变慢烤过程中装药热应力的上升速率,研究了烤燃弹临界响应温度及其三种工况下的响应剧烈程度。结果表明,壳体的约束作用使得装药的热应力随着温度的上升而逐渐增大,根据热应力变化速率的差异,可将整个过程分为6个阶段,其影响因素依次为热膨胀、孔隙率下降、HMX晶型转变、HMX缓慢分解、部分小分子气体泄漏、HMX加速分解,当温度升至208℃时,热应力达到9.2 MPa,装药随即点火;在烤燃弹的装药表面增加热膨胀性较强的硅橡胶包覆层,则会加快装药热应力的增长速率,使得装药的临界点火温度下降,但不会改变装药响应的剧烈程度。

To obtain the change of thermal stress in the slow cook-off test of explosive charge,a set of thermal stress testing de-vice was designed.The change curves of the thermal stress with temperature of octogen(HMX)based aluminized explosive charge under the closed confinement condition were obtained.Through adjusting the volume ratio of inert coating layer and charge,and changing the rising rate of thermal stress in the slow cook-off process,the critical response temperature of cook-off bomb and the intensity of response under three working conditions were researched.The difference of change rate of thermal stress,the whose process can be divided into six stages.Its influencing factors is thermal expansion,porosity decrease,HMX crystal transformation,slow decomposition of HMX,partial small molecule gas leakage,and accelerated decomposition of HMX in the order.When the temperature rises to 208℃,the thermal stress reaches 9.2 MPa and the charge is ignited immediate-ly.Increasing the silicone rubber coating layer with greater thermal expansion on the charge surface of cook-off bomb,can make the growth rate of the thermal stress of charge accelerate and the critical ignition temperature of charge reduce,but the drastic degree of the response of charge does not change.