汽车碰撞中锥形晶胞薄壁金属管吸能特性的仿真研究

摘要

薄壁金属管是汽车碰撞时为安全性所设置的吸能结构件。为优化设计金属薄壁管，该文研究了不同锥度、晶胞数的LD2铝合金锥管的吸能特性。用Hypermesh和Ls—Dyna软件，在轴向和偏斜方向动态载荷两种作用下，以初始峰值载荷（IPL）和比吸能（SEA）来表征吸能特性，进行仿真分析。结果是：对于单、双、四晶胞的锥管，IPL均随着锥度的增加而降低；锥管的IPL均低于直管的IPL，SEA随着锥度的增加而提高；随着斜碰角度的增大，锥度为0．3的四晶胞锥管在斜碰的峰值载荷和比吸能均降低。因此，合理地调整锥度和晶胞数，可以提高薄壁管的吸能特性。%Thin-walled metal tubes are structural parts for vehicle security when automotive collisions occur. This paper investigates the energy absorption characteristics of an aluminum alloy LD2 metallic thin-walled tube with different tapers and cell numbers to optimize the design of the tube. Hypermesh and Ls-Dyna soft wares were used to simulate the dynamic loads in axial and deflective directions with Initial Peak Load (IPL) and Specific Energy Absorption (SEA) characterizing the energy absorption characteristics. The results show that the IPLs of the single-, double-, and fourfold-cell conical tubes reduce with increasing taper, with the IPLs of the taper pipe being lower than those of the straight tube and that the SEA increases with increasing taper. Both the IPL and the SEA in oblique impact decrease as the collision angle increases for fourfold-cell conical tube with taper of 0.3. Therefore, a reasonable adjustment of the tube taper and cell number can improve the energy absorption characteristics of thin-walled tubes.