负泊松比结构填充仿牛角吸能盒的耐撞性数值仿真

Numerical simulation of crashworthiness of imitation horn energy-absorbing box filled with negative Poisson′s ratio structure

为提高吸能盒的耐撞性和吸能性,基于结构仿生学原理提取了决定牛角优良耐撞性能的结构特征参数,结合负泊松比结构的吸能特性,设计了一种以正弦曲边负泊松比结构作为填充芯体的仿牛角吸能盒。利用显式非线性有限元法对仿生吸能盒轴向和横向的变形模式及吸能特性进行了仿真分析,并与等壁厚的方形吸能盒、对角吸能盒和对边吸能盒进行了对比。结果表明,在轴向冲击时,仿生吸能盒的变形模式为渐进叠缩稳态变形,吸能能力明显优于方形吸能盒和对角吸能盒,平均载荷分别是方形吸能盒和对角吸能盒的4.7倍和1.9倍;横向冲击时,仿生吸能盒的结构变形形式较其他3种吸能盒稳定,平均载荷分别是方形吸能盒和对角吸能盒的1.8倍和3.9倍。将牛角结构特征和负泊松比结构共同引入汽车吸能盒设计中可有效改善吸能盒的耐撞性能,为汽车吸能元件的设计提供新的思路。

To improve the crashworthiness and energy absorption performance of the energy-absorbing box,the structural characteristic parameters which determine the good crashworthiness of the horn were extracted based on the structural bionics principle.Combined with the energy absorption characteristics of the negative Poisson′s ratio structure,an imitation horn energy-absorbing box with the negative Poisson′s ratio structure with sinusoidal curves as the filling core was designed.The axial and lateral deformation modes and energy absorption characteristics of bionic energy-absorbing box were simulated by explicit nonlinear finite element method,and compared with those of square energy-absorbing box,diagonal energy-absorbing box and opposite side energy-absorbing box with equal wall thickness.The results show that under axial impact,the deformation mode of the bionic energy-absorbing box is progressive and steady state deformation,and the energy absorption capacity of the bionic energy-absorbing box is obviously better than that of the square energy-absorbing box and the diagonal energy-absorbing box,and the average load is 4.7 times and 1.9 times of the square energy-absorbing box and the diagonal energy-absorbing,respectively.Under the lateral impact,the structural deformation form of the bionic energy-absorbing box is more stable than that of the other three kinds of energy-absorbing box,the average load is 1.8 times and 3.9 times of square energy-absorbing box and diagonal energy-absorbing box,respectively.Introducing the structural characteristics of horn and negative Poisson′s ratio structure into the design of automotive energy-absorbing box can effectively improve the crashworthiness of the energy-absorbing box,and provide a new idea for the design of automotive energy absorption components.