低应变率下改性双基推进剂压缩特性研究

Experimental study on compression characteristics of CMDB propellant at low strain rate

利用万能试验机获取了某含HMX星孔结构改性双基推进剂装药在-40℃、20℃、40℃、50℃和60℃下压缩速率为1 mm·min^(-1)、2.5 mm·min^(-1)和10 m·min^(-1)时的试验数据,得到了该推进剂在压缩时的应力--应变曲线。结果表明:在20℃压缩情况下,应力—应变曲线表现为初始弹性段、屈服增至应变软化阶段、应变强化段和破坏阶段,并且改性双基推进剂的力学性能具有明显的应变率相关性,不同温度下初始弹性模量、屈服应力均随应变率的变化发生改变;温度对改性双基推进剂力学性能的影响较大,随着温度的升高,材料初始弹性模量减小,屈服应力下降,应变软化和应变强化程度发生变化。

The stress-strains of the modified double base propellant charge with star hole were performed on the universal testing machine under different temperature(-40℃,20℃,40℃,50℃)with compression rate of 1,2.5 and 10 mm·min^(-1).The results show that under 20℃compression,the curve exhibits four stages including initial elasticity,yield increase to strain softening,strain strengthening and failure.In addition,the mechanical properties of the modified double-base propellant have obvious strain rate dependence.The initial elastic modulus and yield stress change with the change of strain rate.With the increase of temperature,the results show that the initial elastic modulus decreases,the yield stress decreases,the degree of strain softening and strain strengthening change.