新型负泊松比多孔吸能盒平台区力学性能  

Mechanical properties of new negative Poisson's ratio crush box with cellular structure in plateau stage

作　　者：张伟[1] 侯文彬[1] 胡平[1] 

机构地区：[1]大连理工大学运载工程与力学学部工业装备结构分析国家重点实验室,大连116024

出　　处：《复合材料学报》2015年第2期534-541,共8页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金(11272077);辽宁省"百千万人才工程"(2010921057)

摘　　要：提出了一种具有负泊松比效应的汽车前纵梁吸能盒(NPRC)结构,通过对元胞平台区的失效模式和平台应力的分析,研究了此结构在失效时的力学性能,即等效弹性模量和平台应力在面内加载过程中均能得到一定程度的增强,表现出较好的能量吸收能力。根据NPRC元胞在平台区的力学模型,分别建立了发生弹性屈曲和塑性塌陷时的临界应力公式,得出塑性塌陷是该结构的主要失效模式。通过Matlab程序建立了NPRC元胞的参数化有限元模型,研究了元胞几何参数与平台应力的关系,即元胞的平台应力与长度系数和元胞夹角呈反比,与厚度系数呈正比。通过NPRC结构3×3样件的面内轴向准静态压缩实验验证了有限元分析结果,实验结果表明:NPRC样件等效负泊松比为-11.97,产生密实化现象,平台应力的峰值随着应变的增加逐渐增大,这对提高能量吸收性能具有重要的研究意义。New negative Poisson's ratio crush box(NPRC)structure of vehicle front frame was presented.By studying the failure mode and plateau stress in plateau stage of cell,the mechanical properties of failure were discussed.It can be concluded that the NPRC structure shows better energy absorption capability than usual cellular structure with enhanced equivalent elastic modulus and plateau stress under in-plane loading.With mechanical analytical model of NPRC cell in plateau stage,the critical stress equations of elastic buckling and plastic collapse were developed,the conclusion that plastic collapse is the main failure mode of the structure is also presented.The parametric finite element model of NPRC cell by Matlab software was used to study the relationship between geometric parameters and plateau stress,which indicates that the plateau stress of cell is inversely proportional to length ratio and cell angle and in proportion to thickness ratio.And in-plane axial quasi static compressive experiment using 3×3NPRC sample was carried out to verify finite element analysis results.The results conclude that the NPRC sample has equivalent negative Poisson's ratio(-11.97).The NPRC sample appears densification of cell and peak value of plateau stress increases with the increase of strain,which provides theoretical significance for improving energy absorption performance.

关 键 词：负泊松比 吸能盒 多孔结构 平台应力 塑性塌陷 

分 类 号：U463.326[机械工程—车辆工程]