单基炮药断裂性能之进一步研究

THE FURTHER STUDY ON THE PRACTURE BEHAVIOUR OF SINGLE-BASE GUN PROPELLANTS

本文在7孔单基炮药断裂特性研究的基础上,进一步实验测定了含孔边径向裂纹的单孔管状及多孔柱状单基炮药在不同孔内外压差载荷作用下的应力强度因子 K_I,并采用紧凑拉伸试样实验测定了不同温度下单基炮药的断裂韧性 K_c 值.研究结果表明,在起始使用温度范围(-40℃～60℃)内,单基炮药的 K_c 值为1.88～2.15MPam^(1/2),且 K_c 值随温度的升高而略有增大.单孔管状(如18/1)及多孔柱状(如14/7)单基炮药的相对裂纹长度 c 与临界孔内外压差⊿P_c 的对应关系式分别为⊿P_c 单孔≈5.3/c^(1/2),⊿P_c 多孔≈8.8/c^(1/2).本文为单基炮药的安全使用提供了较可靠的断裂力学强度评估方法.

On the basis of the study of fracture characteristics on 7- perforated single-base gun propellants the stressintensity facters K_I of single-hole tubular or multi-hole cylindric single-base gun propellants which contain radial cracks in their centre hohe by experiments,and the fracture toughness values Kc of the gun pro- pellants by using compact tension specimen under different tempe- ratures have been further measured.The results of study show that Kc of the gun propellants is about 1.88 to 2.15MPam^(1/2) in the range of initial use temperatures (-40℃ to 60℃),and that it will slightly increase along with the raise of temperature.The formulae between the relative crack length Cand the critical pres- sure difference △Pc between inside and outside of the holes are respectively △Pc≈5.3/(?)(sing-holegun tubular propellants,such as 18/1)and △Pc≈8.8/(?)(multi-hole cylindric gun propellants,such as 14/7).The paper presents a quite reliable comment method of frac- ture mechanics for the safe use of thesingle-base gun propellants.