基于近场动力学的船用钢受破片冲击研究

Research on fragmentation impact of marine steel based on peridynamic

为了研究船用钢在非接触式爆炸产生破片冲击下的相关响应模式,更好地提高舰船船体抵抗破片冲击能力,基于近场动力学方法对船用钢受立方体破片冲击的工况进行研究。首先,结合近场动力学理论改进损伤数指标,建立符合船用钢材料规范的船用钢受立方体破片冲击模型;其次,对船用钢在受到不同速度和冲击方式的立方体破片冲击的工况进行物理冲击试验和近场动力学数值模拟,结合数值模拟后的优化损伤图和物理冲击试验后的失效图分析各工况下钢板的失效模式,同时选取船用钢被贯穿失效后的应力图进行各贯穿阶段应力变化分析;最后,使用无量纲法结合线性回归法分析船用钢受破片冲击的临界贯穿速度影响规律。在破片冲击方式对船用钢影响程度方面,立方体破片以棱边对船用钢冲击的工况中钢板损伤程度比以面和尖角冲击的工况分别高出44.6%和29.9%;在破片临界贯穿速度影响规律研究方面,分别得出误差率小于4%的立方体破片以棱边、面、尖角冲击钢板的极限贯穿速度经验公式,并得出在同样条件下立方体破片以棱边对船用钢冲击所需临界贯穿速度最小。采用该近场动力学方法进行破片冲击船用钢的数值模拟研究具有高适用性和准确性,在对船用钢板强度分析时应注重研究立方体破片以棱边冲击钢板的工况。

In order to study the relevant response mode of marine steel under the impact of fragments generated by non-contact explosion,and better improve the ability of ship hull to resist the impact of fragments,Based on the peridynamic method,the working condition of marine steel impacted by cube fragments is studied.Firstly,the damage number index was improved by combining the peridynamic theory,and a cubic fragment impact model of marine steel was established,which was in line with the marine steel material specification;secondly,the physical impact test and peridynamic numerical simula-tion are carried out for the marine steel under the condition of being impacted by cube fragments with different velocities and impact modes.The failure modes of steel plates under various conditions are analyzed through the optimized damage dia-gram affer numerical simulation and the failure diagram after physical impact test.At the same time,the stress diagram of marine steel after penetration failure is selected for the stress change analysis of each penetration stage;finally,the non di-mensional method combined with linear regression method is used to analyze the rule of critical penetration velocity of mar-ine steel impacted by fragments;in terms of the impact degree of fragments on marine steel,the damage degree of steel plate under the condition of cube fragments impacting on marine steel with edges is 44.6%and 29.9%higher than that under the condition of surface and sharp angle impact respectively.In the study of the rule of the influence of the critical penetration velocity of fragments,the empirical formulas of the critical penetration velocity of cube fragments impacting steel plates with edges,surfaces and sharp corners with error rate less than 4%are obtained respectively.Under the same conditions,it is con-cluded that the critical penetration velocity required for the impact of cube fragments on marine steel with edges is the min-imum.The numerical simulation of fragment impact on marine steel using this peridynamic method has high applicability and accuracy.When analyzing the strength of marine steel plates,attention should be paid to the study of the working condi-tion of cube fragments impacting steel plates with edges.