不同截面双胞锥管在动态轴向和斜向载荷作用下的耐撞性

摘要

为提高结构的安全性,薄壁管越来越多地应用于汽车工业.本文研究双胞锥管在动态轴向和斜向载荷作用下的失效行为,并利用LS-DYNA验证的有限元模型对不同截面(圆形、方形、六角形、八角形、十角形)管材的耐撞性进行了数值分析.然后通过减少远端截面尺寸来优化锥管的几何形状,同时保持重量不变.结果表明,八角形圆锥形管比其他管更适合作碰撞能量吸收器.方管和圆管呈现金刚石变形模式,而其他管呈蛇腹式失效.利用TOPSIS决策方法分析数值结果,以选择最有效的吸能器.%Thin-walled tubes are increasingly used in automobile industries to improve structural safety. The present work deals with the collapse behavior of double-cell conical tubes subjected to dynamic axial and oblique loads. Crashworthiness of these tubes having different sections (e.g., circular, square, hexagonal, octagonal, decagonal) was numerically investigated by using an experimentally validated finite element model generated in LS-DYNA. Geometry of these tubes was then optimized by decreasing the cross section dimensions at the distal end while the weight remained unchanged. Octagonal conical tube was finally found to be more preferable to the others as a collision energy absorber. In addition, square and circular tubes showed diamond deformation mode, while the other tubes collapsed in concertina mode. A decision making method called TOPSIS was finally implemented on the numerical results to select the most efficient energy absorber.