新型多边形锥管的准静态压缩与耐撞性分析

Quasi-static compression and crashworthiness analysis of new polygonal tapered tubes

在车辆的耐撞性研究中,锥形薄壁管因其具有稳定的力-位移曲线和变形过程,被认为是轴向加载下的一种理想的能量吸收器。设计了两种类型的新型多边形锥管,通过在传统的多边形锥管上引入特殊的折纸图案,诱导结构按预制的折纸图案发生变形,从而提高其在准静态轴向压缩条件下的耐撞性;并通过准静态压缩实验研究了截面边数和壁厚对其变形模式和耐撞性的影响。结果表明:截面边数的增加使结构更容易发生局部屈曲和塑性失稳;增加壁厚会使局部屈曲和塑性失稳相对减弱,但结构会产生更多的裂缝。截面边数N对耐撞性的影响主要体现在初始峰值力上,初始峰值力随N的增加而增加,平均压缩力、比吸能和压缩力效率随N变化无明显规律;壁厚t对耐撞性有较大的影响,初始峰值力、平均压缩力和比吸能都随t的增加而增加,压缩力效率随t增加无明显规律。同时,通过传统六边形锥管(CH6)与两类新型六边形锥管(N6M1和N6M2)对比发现,折纸图案的引入在降低初始峰值力、提高平均压缩力和压缩力效率方面有显著优势。

In the crashworthiness study of vehicles,tapered thin-walled tube is considered as an ideal energy absorber under axial loading because of its stable force-displacement curve and deformation process.Two types of new polygonal tapered tubes are designed.By introducing special origami patterns on the traditional polygonal tapered tubes,the structures are induced to deform according to the prefabricated origami patterns,so as to improve their crashworthiness under quasi-static axial compression.The effects of the number of section edges and wall thickness on the deformation mode and crashworthiness of the specimens were studied.The results show that the increase of the number of section edges makes the structure more prone to local buckling and plastic instability.Local buckling and plastic instability are relatively weakened by increasing wall thickness,but more cracks are generated in the structure.The influence of the number of section edges N on crashworthiness is mainly reflected in the initial peak force.The initial peak force increases with the increase of N,while the average compression force,specific energy absorption and compression force efficiency have no obvious rule with the increase of N.The wall thickness t has a great influence on crashworthiness.The initial peak force,average compressive force and specific absorption energy all increase with the increase of t,while the efficiency of compressive force has no obvious rule with the increase of t.Meanwhile,by comparing the traditional hexagon tapered tube(CH6)with two new types of hexagon taper(N6M1and N6M2),it can be seen that the introduction of origami pattern has significant advantages in reducing the initial peak force,improving the average compression force and compression force efficiency.