水下爆炸冲击波载荷作用下冰层破碎特性及其影响因素

水下爆炸破冰是复杂的爆破工程,为了研究冰层在水下爆炸冲击波载荷作用下的破碎特性及规律,利用几何动力分析软件LS-DYNA对水下爆炸破冰的过程进行数值模拟,并将计算结果与实验结果进行对比,误差在8%以内,验证了数值模型的有效性。根据本文中的建模方法及建立的模型,计算不同的实验工况:实验场地环境不变,调整爆距分析不同爆距下冰层破碎特性;调整药量、爆距和冰厚,通过正交设计方法设计9组实验方案,应用灰色系统理论对3种因素进行分析,建立了各个因素与破冰半径之间的灰色关联度系数及灰色关联度。分析结果表明:药量为100 g,冰厚为29 cm,水深为2.9 m,爆距范围为0.3~1.5 m破冰的半径范围为0~1.1 m,最佳爆距范围在0.3~0.45 m之间;根据以上9种工况的分析可知,药量(100、200、300 g)、爆距(0.3、0.6、0.9 m)和冰厚(24、28、32 cm)对破冰半径的影响的主次关系依次为爆距、药量、冰厚。

Fragmentation of ice cover subjected to underwater explosion shock wave load and its influence factors

Ice breaking by blasting is a complex process in underwater explosion engineering.In this study we examined the fragmentation characteristics of ice cover with underwater explosion shock wave and simulated the process of underwater explosion breaking ice process using LS-DYNA.We also compared the simulation result with the experimental data and found the min good agreement.Based on this we verified the simulation model and calculated different conditions.Then,keeping the test environment unchanged,we set different detonation distances,and calculated the radius of the ice breaking hole;varying the charge dosage,the detonation distance and the ice thickness,we designed nine group simulation conditions by the orthogonal design method,and analyzed the gray relational degrees and gray incidence coefficients between radius of breaking ice hole and different factors at different levels using the gray system theory.The analytical results showed that,at 100 g of the dosage,the ice thickness is 29 cm,the water depth is 2.9 m,the detonation distance range is 0.3 1.5 m,the radius range of breaking ice hole is 0 1.1 m,and the best detonation distance is between 0.3 0.45 m.According to the analysis of the above nine simulation conditions,the influencing factors that matter most remarkably in underwater ice breaking are the detonation distance(0.3,0.6,0.9 m),the dosage(100,200,300 g),and the ice thickness(24,28,32 cm),in order of their importance.