弹体对混凝土材料先侵彻后爆炸损伤破坏效应的数值模拟研究

基于Kong-Fang混凝土材料模型和LS-DYNA的流固耦合和重启动算法，开展了某新型钻地武器先侵彻后爆炸对混凝土靶体的毁伤破坏效应研究。通过模拟大口径缩比弹侵彻实验和预制孔爆炸实验，验证了材料模型及其参数的可靠性。在此基础上，进一步对预制孔装药爆炸建模、不考虑弹壳的重启动建模和考虑弹壳的重启动建模3种方法进行了比较。数值计算结果表明，由于爆轰产物的外泄，不考虑侵彻预损伤的预制孔装药爆炸方法得到的爆坑直径仅为3倍弹径，且损伤破坏模式与其他2种方法得到的损伤破坏模式区别较大。重启动建模方法继承了弹体侵彻过程中累积的损伤，爆坑直径在原有侵彻损伤破坏的基础上明显增大；且由于弹壳变形破碎消耗部分能量，考虑弹壳时模拟得到的爆坑直径（约14.5倍弹径）略小于不考虑弹壳时模拟得到的爆坑直径（约16倍弹径）；但由于破碎弹头的二次侵彻作用，考虑弹壳时模拟得到的爆坑深度比不考虑弹壳时模拟得到的爆坑深度增加约5%。上述研究结果可为进一步开展钻地武器先侵彻后爆炸毁伤破坏效应的实验研究提供参考。

Numerical investigation on damage and failure of concrete targets subjected to projectile penetration followed by explosion

Based on the recently proposed Kong-Fang concrete material model and the fluid structure interaction (FSI) and restart algorithms available in the LS-DYNA, the damage and failure of concrete targets subjected to projectile penetration followed by explosion were numerically investigated. The numerical model, material models along with the corresponding parameters were firstly validated by comparing the numerical simulation results of the large-caliber projectile penetration experiment and the charge explosion test of a concrete target with a precast hole to the corresponding test data in terms of the penetration depth and scabbing depth, respectively. Then numerical simulations of the damage and failure in concrete targets struck by a typical warhead were conducted using three different modeling methods, i.e., charge explosion in a concrete target with a precast hole, charge explosions without and with projectile shell using the restart algorithm. The numerical results demonstrate that the crater diameter of the concrete target caused by explosion is only three times the projectile diameter when the pre-damage during the penetration process is not considered, and the damage and failure patterns are different from those using the other two methods. The numerically predicted crater diameter is very large when considering the pre-damage during the penetration process, as expected. However, the final crater diameter when the projectile shell is considered (about 14.5 times the projectile diameter) was slightly smaller than that without the consideration of projectile shell (around 16 times the projectile diameter), which mainly because part of the explosion energy is dissipated by the deformation and fracture of the projectile shell. The predicted crater depth with the consideration of projectile shell is increased by 5% compared with that ignoring the projectile shell, mainly due to the secondary penetration of the fragmentized warhead. The present numerical results can provide a reliable reference for further experimental investigation on the damage and failure of concrete targets subjected to projectile penetration followed by explosion.