带装甲钢背板的钢纤维混凝土靶抗侵彻试验及数值模拟研究

为了研究钢纤维混凝土抗侵彻性能,对带装甲钢背板的高强度钢纤维混凝土靶进行12.7 mm穿甲弹、长杆弹高速撞击侵彻试验。根据背靶侵彻深度试验结果,采用防护系数评估复合靶的抗侵彻性能。采用细观离散元模型Lattice Discrete Particle Model、弹塑性模型和Johnson-Cook屈服准则分别描述钢纤维混凝土、弹体和装甲钢靶的材料力学响应,建立了混凝土侵彻问题的有限元-离散元耦合数值仿真模型。通过对比钢纤维混凝土破坏形态和背靶侵彻深度,验证仿真模型对于钢纤维混凝土侵彻问题的适用性。针对3种代表性侵彻工况,模拟分析复合靶间隙以及钢纤维含量对于侵彻响应的影响。仿真结果表明:相比含间隙的复合靶,无间隙的约束条件能够明显减小背靶侵彻深度;钢纤维含量对于背靶侵彻深度几乎没有影响而对混凝土靶破坏形态有较大影响。进一步仿真分析12.7 mm穿甲弹贯穿钢纤维混凝土靶板响应影响因素,得到:圆柱靶直径大于30倍弹径时,弹体贯穿出靶速度趋于收敛;随着靶体厚度增小,剩余速度与撞击速度趋近于线性关系。

Experiments and Numerical Simulation of Penetration Resistance of Steel Fiber Reinforced Concrete Target Backed by Steel Plate

In order to investigate the penetration resistance of steel fiber reinforced concrete (SFRC),12.7 mm armor-piercing projectiles and long rod projectiles are used to penetrate a high strength fiber reinforced concrete backed by armor steel in high speed impact test.The penetration resistance of composite target is evaluated using protection factor according to the penetration depth of rear target.The lattice discrete particle model (LDPM) is introduced to model fiber reinforced concrete,and the elastic-plastic model and Johnson-Cook criterion are used to describe the projectile and armor steel.A numerical simulation model for penetration into concrete target is established.The feasibility of numerical model for simulation of penetration into fiber reinforced concrete is validated in terms of penetration depth and concrete target damage mode.The effects of internal gap and fiber content of composite target on penetration response in 3 typical penetration tests are simulated and analyzed.The numerical results show that,for the composite target without gap,the residual penetration depth of rear target can be effectively reduced,and the fiber reinforcement has no effect on the penetration depth but affects the concrete damage mode significantly.Further numerical analyses of fiber reinforced concrete target perforated by 12.7 mm armor-piercing projectiles indicate that the perforation velocity of projectile tends to converge if the diameter of cylindrical target is 30 times larger than projectile diameter,and the residual velocity approximates a linear relationship with impact velocity with the decrease in target thickness.