拉拔成型无氧铜管在爆轰加载下的膨胀及断裂特性研究

为了探索拉拔成型无氧铜管是否满足标准圆筒试验的延展性要求，采用未经二次锻造的粗晶软态无氧铜，通过拉拔成型工艺加工成25 mm圆筒试验用的标准铜管。采用超高速分幅相机及扫描相机分别观测装填TNT炸药及JO-159炸药条件下的铜管膨胀及断裂过程，对比典型高应变率范围内铜管的断裂应变、裂纹扩展方向等差异，并分析铜管应变能对炸药驱动性能表征参数的影响。结果表明：TNT炸药爆轰加载下，铜管裂纹主要沿母线形成及扩展，其破片主要呈条状；而JO-159炸药爆轰加载下，铜管环向应变率及轴向应变率分别约为TNT炸药加载工况的1.34倍和2倍， 其断裂带易出现较为复杂的交错状态，形成密集小破片；这两种炸药爆轰下，该铜管的断裂直径均达到了初始直径的3倍，且表征炸药驱动性能的格尼速度未发生明显变化，因此可以满足一般高能炸药圆筒试验的要求。

Research on the Expansion and Fracture Characteristics of Drawing-molded Oxygen-free Copper Tubes under Detonation Loading

In order to explore whether the drawn-molded oxygen-free copper tube meets the ductility requirements of standard cylinder test, a standard copper tube for SymbolFA@25 mm cylinder test was made of coarse-grained soft oxygen-free copper without secondary forging by using the drawing process. The high-speed framing camera and scanning camera were used to observe the expansion and fracture processes of copper tube under detonation loading of TNT and JO-159 explosives, and compare the difference of fracture strain and the direction of crack propagation in the typical high strain rate range. The influence of strain energy of copper tube on the characterization parameters of driving performance of explosive was also analyzed. The results show that the cracks of copper tubes are mainly formed and expanded along the busbar and the fragments are mainly strip-like under the detonation loading of TNT explosive. However, under the detonation loading of JO-159 explosive, a more complicated staggered state arises in the fracture zone, and the copper tube expands to form dense small fragments. The main reason for this phenomenon is that the circumferential and axial strain rates of copper tubes under detonation loading of JO-159 explosive are 1.34 and 2 times of those under detonation loading of TNT. Under the detonation loading of these two kinds of explosives, the fracture diameter reaches 3 times of the initial diameter, and the Gurney speed, which characterizes the driving performance of explosives, is not changed significantly. Therefore, the copper tubes can meet the requirements of the general high-energy explosives for cylinder test.