错位多次打击下UHPC靶体损伤破坏效应的数值模拟研究

Numerical Investigation on Damage and Failure of UHPC Targets Subjected to Dislocation Multi-Attacks

基于LS-DYNA三维数值建模方法和修正的Kong-Fang混凝土材料模型,考虑多次打击时弹着点的二维正态分布规律,开展了某弹体错位多次打击下超高性能混凝土靶损伤破坏效应的数值模拟研究。首先对已有弹体先侵彻后爆炸一次打击试验进行了数值模拟,验证了数值建模方法和材料模型参数选取的准确性。在此基础上,开展了10组(圆概率误差(circular error probable,CEP)为3 m时5组,CEP为1 m时5组,每组随机生成3个弹着点)错位多次打击工况的数值计算,探讨了CEP和打击次数对靶体损伤破坏与侵彻深度的影响。数值模拟结果表明:第1枚弹体侵彻后的后续计算过程中,损伤演化均沿第1枚弹体侵彻后的材料损伤区域继续发展,随着打击次数增加,侵彻深度逐渐增加;当多次打击过程的CEP相同时,考虑爆炸工况时计算的侵彻深度比不考虑爆炸工况时大;CEP越小,相对侵彻深度越大,当CEP为1 m时,相对侵彻深度约为1.7,当CEP为3 m时,相对侵彻深度约为1.2。研究结果表明,在多次打击下,现有防护设计规范中遮弹层厚度的设计方法偏危险。

Based on the LS-DYNA three-dimensional numerical modeling method and the modified Kong-Fang concrete material model,the numerical investigation on damage and failure of ultra-high performance concrete(UHPC)targets subjected to dislocation multi-attacks was carried considering the two-dimensional normal distribution of strike points.The numerical model and material models along with the corresponding parameters were firstly validated by comparing the numerical simulation results of the UHPC targets subjected to projectile penetration followed by explosion to the corresponding test data.Then numerical simulation of the damage and failure in UHPC targets under the multi-attacks by a typical warhead were conducted with 10 groups different circular error probable(CEP)to discuss the effects of the CEP and strike times on the damage and penetration depth.The numerical results demonstrate that the damage evolution caused by the subsequent projectile penetration and explosion continues to develop along the damage area caused by the first projectile penetration.The penetration depth gradually increases as the number of strike increases.The penetration depth calculated with explosion is larger than that calculated without explosion when the CEP is same during multi-attacks.When CEP is equal to 3 m and 1 m,the relative penetration depth is about 1.2 and 1.7,respectively.In other words,the relative penetration depth increased with decreasing of the CEP.The research conclusion shows that the design method of shielding layer thickness in the existing protective design code is dangerous subjected to multi-attacks.