空中近距爆炸下加筋板架的毁伤模式仿真研究

为研究导弹战斗部近距爆炸下舰船舷侧板架结构的毁伤模式及其转化规律,通过有限元模拟,研究了柱状炸药在矩形加筋板架中心正上方爆炸时加筋板架的毁伤模式及不同毁伤模式之间转化的临界爆距,分析了比例距离r和损伤因子Df对毁伤模式的影响,得到了关于D0f.5和r的毁伤模式判别图,提出了不同毁伤模式的判别方法,给出了预测不同毁伤模式之间转化的临界爆距的计算公式。结果表明,对于给定的药量和板架结构,若(rD0f.5)>0.023 3 m/kg1/3,则随爆距的减小,加筋板架依次经历模式Ⅰ(仅出现塑性大变形)、模式Ⅱ(长边中间出现拉伸撕裂)和模式Ⅲ(中央出现破口)这3种毁伤模式;若(rD0f.5)0.023 3 m/kg1/3,则随爆距的减小,加筋板架仅依次经历模式Ⅰ和模式Ⅲ。

Numerical study on the damage mode of stiffened plates subjected to close-range air-blast loading

To explore the damage modes as well as the transitions between them for stiffened plates subjected to close-range air-blast loading produced by the explosion of missile warheads, finite element simulations were carried out to investigate the damage modes and the critical stand-off distances between different modes in the case of the explosion over the centre of the stiffened plates. The influences of the scaled distance and the dimensionless damage factor Df were analyzed. A damage mode map related to Df-0.5 and was obtained. The criteria of different damage modes was proposed. Meanwhile, equations were presented to determine the critical stand-off distances between different damage modes. Results show that, for a gvien charge and a stiffend plate, if the condition ( Df0.5)>0.0233m/kg1/3 is fulfilled, the stiffened plate will experience in sequence Mode I (large plastic deformation), Mode II (tensile tearing at the middle point of the long boundary) and Mode III (crevasse at the centre of the plate) as the stand-off distance reduces. Otherwise, if ( Df0.5)≤0.0233m/kg1/3, only Mode I and Mode III were successively underwent by the stiffened plate as the stand-off distance decreases.