爆破荷载作用下脆性材料水耦合断裂行为

Water Coupling of Brittle Materials under Blasting Load Fracture Behavior

通过水介质耦合爆破实验和数值方法研究了爆破荷载条件下的动态压裂行为和裂纹扩展行为。实验以透明均质的PMMA为实验材料,水为耦合介质,通过DDNP起爆来开展实验。视觉观察是理解爆破荷载下动态压裂和裂纹传播过程的有用手段,因此在爆破试验中借助高速摄像机观察了压裂和裂纹传播过程,从定量和定性两方面对裂纹扩展行为进行了分析。结果表明:在爆破荷载作用下,炸药爆炸后产生的裂纹主要来源于水楔作用且作用时间远大于类似水激波的作用时间,试件中产生大量条形裂纹以及大小不一的耳状裂纹,并且水介质耦合能够得到较为均匀对称的爆破效果。利用商用数值模拟软件AUTODYN进行了数值模拟再现了试件的裂纹扩展过程,得到爆破过程中的孔壁压力,与实验结果对比发现相似度较高。

The dynamic fracturing behavior and crack propagation behavior under blasting load were studied by water medium coupling blasting experiment and numerical method.Transparent and homogeneous PMMA was used as the experimental material,water as the coupling medium,and DDNP initiation was used to carry out the experiment.Visual observation is a useful means to understand the process of dynamic fracturing and crack propagation under blasting load.Therefore,the process of fracturing and crack propagation was observed by means of high-speed camera in blasting test,and the crack propagation behavior was analyzed quantitatively and qualitatively.The results show that under the action of blasting load,the cracks produced by explosive explosion mainly come from the action of water wedge,and the action time is much longer than that of similar water shock wave.A large number of strip cracks and ear cracks with different sizes are produced in the specimen,and the water medium coupling can obtain more uniform and symmetrical blasting effect.The crack propagation process and the hole wall pressure during blasting are simulated by using AUTODYN,which is a commercial numerical simulation software.The similarity is higher than that of the experimental results.