落锤冲击作用下充液半球壳的实验和数值分析  

Numerical simulations for deformations and energy absorption of liquid-filled thin hemispherical shells under a drop hammer impact

作　　者：管文博 杨会伟[1] 胡建星 韩志军[1] 路国运[1] 

机构地区：[1]太原理工大学应用力学与生物医学工程研究所,太原030024

出　　处：《振动与冲击》2014年第21期148-154,共7页Journal of Vibration and Shock

基　　金：国家自然科学基金项目(11372209);山西省回国留学人员科研及择优资助项目(2013-044)

摘　　要：采用数值仿真方法对单层内空、单层充液和双层充液不锈钢半球形薄壳在冲击荷载下的动力学响应进行了研究并实验结果进行了比较,验证了数值模拟的有效性。利用验证的模型对落锤冲击三种壳结构的变形模态及其变形特点和能量吸收进行的比对研究。分析发现:内空半球壳在冲击作用下产生镜面反射式的下凹变形,冲击结束后没有明显回弹,壳体横截面没有发生扩展;而对于内充液体的壳体,由于内部液体的作用其反射下凹边缘有了较大的过渡区,在"棱区"边缘伴有向外扩展,如果冲击能量足够,冲头会对镜面反射下凹边缘区产生熨平作用,冲击结束后有明显的回弹。单层内空壳体具有较好的吸能能力,但会使壳体产生较大的顶点位移,极大的压缩了壳内的有效防护空间。双层充液半球壳可以在产生不大的变形情况下吸收较大的冲击能量,并在内壳形成一定的防护空间,而单层充液壳体其吸能及变形情况与双层壳的外壳基本一致。Here,numerical simulations were performed to study dynamic responses of a single-layer empty thin-wall hemispherical shell,a single-layer liquid-filled thin-wall hemispherical shell and a double -layer liquid-filled thin-wall hemispherical shell under impact loading.They were subjected to impact loading of a drop hammer then the modes and features of their deformation were obtained in all the cases.Numerical simulations were done using ANSYS and LS-DYNA,then the deformation and energy absorption of three kinds of hemispherical shells were obtained.Numerical results showed that the concave deformations with a style of mirror-reflection appear in the single-layer empty hemispherical shell due to impact loading;for the single-layer fluid-filled hemispherical shell,due to the action of liquid inside,there is a larger transition zone on the edge of its concave deformations,if the impact energy is sufficient,the concave edge is made to be flat by the hammer;the single-layer empty hemispherical shell has a better capability of energy absorption,but its vertex displacement is bigger,so the effective protection space in it decreases;the double-layer liquid-filled hemispherical shell can absorb most of impact energy with smaller deformations,a certain protection space can be formed in it;the energy absorption and deformations of the single-layer liquid-filled hemispherical shell are similar to those of the double-layer liquide-filled hemispherical shell.

关 键 词：半球壳 充液 冲击 吸能 

分 类 号：O347.3[理学—固体力学]