重复爆炸载荷作用下薄壁方管动力响应研究  

Research on the Dynamic Response of Thin-walled Square Tube under Repeated Blast Loads

作　　者：周游 纪冲 王雷元[1] 宋诗谦 马华原 ZHOU You;JI Chong;WANG Leiyuan;SONG Shiqian;MA Huayuan(Northwest Institute of Nuclear Technology,Xi an 710024,Shaanxi,China;College of Field Engineering,Army Engineering University of PLA,Nanjing 210007,Jiangsu,China)

机构地区：[1]西北核技术研究所,陕西西安710024 [2]陆军工程大学野战工程学院,江苏南京210007

出　　处：《兵工学报》2019年第9期1871-1880,共10页Acta Armamentarii

基　　金：国家自然科学基金项目(51678567、11102233)

摘　　要：薄壁方管作为一种典型工程构件,在建筑、海洋、航天等领域应用广泛,其结构面临遭受重复爆炸的风险,开展薄壁方管在重复爆炸载荷作用下的动力响应研究具有重要现实意义。采用实验与数值模拟相结合的方法,对比分析了薄壁方管在单次和重复爆炸载荷作用下的动力响应。将壁厚4mm、横截面边长100mm的薄壁方管置于爆炸场中进行冲击实验,并利用非线性动力有限元程序LS-DYNA完全重启动功能及流体与固体耦合算法,对薄壁方管在单次爆炸和重复爆炸载荷下的非线性动力响应过程进行三维数值模拟;描述了方管在不同爆炸次数下的动力响应及损伤变形,给出了一种通过损伤因子反映爆炸载荷作用后材料损伤劣化的数值计算方法。研究结果表明:方管在重复爆炸作用下的变形会产生损伤积累;相同爆炸载荷作用下已变形损伤的方管相对无损方管其有效应变增量更大,在迎爆点周围区域、侧边以及塑性铰位置,前者有效应变增量达到了后者的2.47~3.88倍,容易引起方管更严重的毁伤;两侧边是方管较脆弱的区域,极易因应力集中产生较大的塑性应变,需要特别加强防护。As a typical engineering component,thin-walled square tube is widely used in construction,ocean and aerospace fields.Its structure may be subjected to the repeated blast loads.It is of practical significance to the research on dynamic response of thin-walled square tube under repeated blast loads.Experimental and numerical investigations were carried out on the dynamic response of thin-walled steel square tubes subjected to single and repeated blasting loads.The impact experiments of thin-walled square tube with 4 mm in wall thickness and 100 mm in cross-section width were made in the explosion field.Based on the full restart function of LS-DYNA and Euler-Lagrange coupling method,the dynamic responses of square tubes subjected to single or repeated blast loads laterally are numerically simulated,and the damage effects under different explosion numbers are described.A numerical method is proposed to reflect the material damage after blast load by damage factor.The results show that the deformation of square tubes subjected to repeated blast loads causes a damage accumulation.Under the same blast load,the deformed square tube has bigger effective strain increment than that of undamaged square tube.In the area around the mid-point,the sides and the plastic hinge position of square tube,the effective strain increment of the former is 2.47-3.88 times of the latter,which may cause the square tube to be damaged more seriously.The two sides of square tube are the weak areas,so it is easy to produce large plastic strain due to stress concentration,and a special protection is needed.

关 键 词：薄壁方管 重复爆炸 动力响应 完全重启动 材料损伤 

分 类 号：O383.3[理学—流体力学]