内爆和柱壳条件下无氧铜的层裂特性

Spall of cylindrical copper by converging sliding detonation

利用任意反射面位移干涉系统(DISAR)激光测速技术,成功地获得了滑移内爆加载和柱壳结构条件下无氧铜的内表面(自由面)速度剖面,并对其层裂特性进行了初步分析。结果表明:(1)在固定炸药和改变无氧铜圆管壁厚条件下,层裂片厚度δ随着圆管壁厚h的减小而增加;以圆管壁厚h为参照进行归一化,则相对层裂片厚度(δ/h)随相对装药厚度(he/h)的增大而增加,这种规律与以往对20钢的研究结果一致,但圆管发生层裂的临界条件,却显示出明显的材料相关性。(2)初步来看,无氧铜的层裂强度对结构的依赖性不明显,而与加载脉冲的幅值和宽度相关。(3)受无氧铜粘性和Taylor波衰减的影响,无氧铜的层裂强度随管壁厚度的增加而略有降低;同时,材料分散性也对此有一定影响。

The dynamic tensile fracture of cylindrical OFHC copper subjected to converging waves induced by sliding detonation was experimentally investigated. The inner surface （or free-surface） velocity profiles were measured by the displacement interferometer system for any reflector （DISAR）. Analysis to velocity profiles gives some lights on the spalling characteristics of copper. Firstly, if the thickness 6＇ of the spall scab and the high explosive （HE） thickness he are both divided by the wall thickness h of OFHC copper, it follows that the relative thickness 8/h of the spall scab increases with the relative HE thickness he/h. This accords with the research results of the steel cylindrical shell under the similar loading, however, the critical value of he/h for shell spalling is dependent on its material. Secondly, by comparing with other literatures, it can be seen elementarily that the spall strength of OFHC copper depends weakly on the geometric structure but mainly on the pressure and duration of impact loading. Lastly, the spall strength of OFHC copper is slightly lowered when its thickness increases, where material viscosity and Taylor triangular wave attenuation both contribute, also the dispersion of material.