舰船舱内爆炸载荷特征与板架毁伤规律分析

Analysis on characteristics of blast loading and stiffened plate damage due to internal blast in ship

[目的]炸药在自由场、舱室内爆炸时,载荷特征存在很大差别。[方法]模拟不同药量炸药在自由场、密闭舱室与开口舱室中爆炸的过程,并对比数值计算载荷与亨利奇公式计算结果,分析炸药在密闭舱室以及开口舱室内的载荷特征。[结果]研究表明,在密闭舱室中,冲击波在角隅处形成汇聚压力,其在角隅处的冲击波总冲量约为板架中心处冲击波总冲量的1.45倍,而开口舱室角隅处的压力并不明显;与密闭舱室相比,开口舱室的反射压力峰值与准静态压力值均较小;开口舱室的冲击波总冲量约为密闭舱室的20%;密闭舱室板架的失效模式为板架沿加强筋发生塑性变形,沿角隅发生撕裂;开口舱室角隅处并未发生撕裂,但开口边缘处发生了外翻变形;只考虑冲击波作用时,采用数值模拟方法得到的板架中心最大变形值与简化计算方法得到的值比较接近,但在同时考虑冲击波、准静态压力作用时,误差较大。[结论]研究结果可为舱室内爆载荷的特征与板架毁伤规律提供较为合理的预报。

[Objectives]Blast loads differ according to whether the blast takes place in a free field orcabin.[Methods]Dynamic software is used to simulate different explosive charge blasts in a free field,closed cabin and open cabin. The numerical results are then compared with the Henrych formula results,and the load characteristics of the open cabin and closed cabin are analyzed. [Results]The researchshows that the shockwave gathers in the corner of the closed cabin. The total impulse of the shockwave inthe corner is about 1.45 times greater than the total impulse at the center of the plate,while the pressure inthe corner of an open cabin is not obvious. The peak values of the reflected pressure and quasi-staticpressure in a closed cabin are smaller than those in an open cabin. The total impulse of the shockwave inthe open cabin is about 20% that of the closed cabin. The pattern of plate damage in the closed cabin ismainly the plastic deformation of the plate frame along the stiffeners and the plate tearing along the corner;the tear does not occur in the closed cabin corner,but valgus deformation occurs at the edge of the opencabin;the maximum deformation value of the plate center obtained by the numerical simulation method isclose to that obtained by the simplified method when only the impact of the shockwave is considered. Whenboth the impact of the shockwave and quasi-static pressure are considered at the same time,the errormargin is larger.[Conclusions]The results of this paper can be used to predict the characteristics of blastloading and stiffened plate damage.