反转螺旋型薄壁结构碰撞吸能特性的优化设计

Optimum Design on the Crash Energy Absorbing Ability of Reverse Spiral Cylindrical Thin-walled Structure

为了使汽车前纵梁在正面碰撞过程中吸收更多的能量,进而达到提高汽车被动安全性能的目的,将折纸工程中的反转螺旋型薄壁结构引入汽车前纵梁的结构设计,利用数值模拟与优化设计相结合的方法,研究和开发一种新型高效吸能结构。为此,根据反转螺旋型薄壁结构的不同形状参数建立相应的有限元模型,利用非线性有限元软件LS-DYNA软件进行碰撞仿真,并以反转螺旋型薄壁结构的截面形状参数、旋角及分段数作为设计变量,以吸能量的最大化为目标函数,利用响应曲面法进行优化计算。得到的最优结构在碰撞过程中,压溃皱纹依次出现在反转螺旋型薄壁结构的折痕处,有效地避免了细长薄壁结构的失稳倒伏现象,是一种吸能效率较高的变形模式。同时,吸能过程平稳,在整个碰撞过程中都保持了良好的吸能特性,与传统的矩形断面结构相比吸能量有了显著的提高。

In order to make the front side member of the car to absorb more energy during frontal crash, thus achieve the purpose of the improvement of the car＇s passive safety performance, the reverse spiral cylindrical structure of origami engineering is applied to the structure design of front side member, by using the numerical simulation and optimization design method, to research and development a new type of highly efficient energy absorbing structure. The corresponding finite element model is established, according to the different design parameters of the reverse spiral cylindrical structure, then using LS-DYNA software for the crash simulation, and take the reverse spiral origami structure of different cross-section parameter, rotation angle and the number of segments as design variables, the maximization of energy absorbing as the objective function, response surface method is used for optimization calculation. During the crash, the optimal structure＇s crushing wrinkles appear in the folds of the structure, avoiding the slender thin-walled structure instability phenomenon effectively, which is a kind of efficient energy absorption＇s deformation mode. Meanwhile, endergonic process smoothly and keep the good energy absorption properties in the entire process of crash, the optimization results that the optimal structure is capable of energy absorption more than that of rectangular cross sectional structure that is used generally.