HTPB推进剂冲击发火判据的试验研究

Experimental Study on the Criterion of Impact Ignition of HTPB Propellant

为探究某型HTPB推进剂冲击发火的判据,对落锤试验进行了改进,在底座中引入聚偏二氟乙烯膜(PVDF)压电膜,测量推进剂受落锤冲击下的应力峰值,得到50%冲击发火的临界落高与应力;基于分离式霍普金森压杆的冲击发火试验,对比并分析了在不同的冲击应力加载条件下,推进剂临界冲击发火的影响条件,并给出该型推进剂的50%冲击发火判据。结果表明,应力峰值与特性落高的关系满足σ=175.09 H 0.5,50%特性落高为75 cm,100%不发火的最大落高为68 cm。在20、30和40 cm子弹冲击条件下,推进剂50%冲击发火的应力峰值分别为2760、2410和2120 MPa,作用持续时间分别为76、100和130μs,推进剂的冲击发火与推进剂受到的冲击应力大小和作用时间直接相关,通过σ^2τ=K判据可以较好地判断推进剂的冲击发火临界条件,且确定了K值为574.6MPa^2·s。

In order to explore the criterion of impact ignition for a certain type of HTPB propellant,the drop hammer test was improved.The polyvinylidene fluoride(PVDF)piezoelectric film was introduced into the base to measure the stress peak of the propellant under the impact of the drop hammer,and the critical drop height and stress of 50%impact ignition were obtained.The height and stress information were compared with the impact ignition test based on the split Hopkinson pressure bar.The conditions affecting the critical impact ignition of the propellant under different impact stress loads were analyzed,and 50%impact ignition criterion of the certain type of propellant was concluded.The results show that the features of drop height and stress peak meet the relationship of σ=175.09 H 0.5,the drop height of 50%is 75 cm,and the maximum drop height of 100%no-ignition is 68 cm.Under the impact conditions of 20,30 and 40 cm bullet,the stress peak of 50%impact ignition of propellant is 2760,2410 and 2120 MPa,respectively,and the effect lasts for 76,100 and 130μs.The impact ignition of the propellant is directly related to the impact stress and the action time of the propellant.The impact ignition of the propellant can be judged by the criterion of σ^2τ=K,and the value of K is determined to be 574.6 MPa^2·s.