闭孔泡沫铝的塑性泊松比  

PLASTIC POISSON'S RATIO OF CLOSED-CELL ALUMINUM FOAMS

作　　者：张乐[1] 张健[2] 赵桂平[1] 

机构地区：[1]西安交通大学机械结构强度与振动国家重点实验室,西安710049 [2]西安理工大学土木建筑工程学院西北旱区生态水利工程国家重点实验室培育基地,西安710048

出　　处：《固体力学学报》2015年第3期244-250,共7页Chinese Journal of Solid Mechanics

基　　金：国家自然科学基金项目(11372237;11402197);国家重大基础研究计划项目(2011CB610305)资助

摘　　要：闭孔泡沫铝的塑性泊松比在常见的唯象可压缩本构关系中是一个重要的参数,然而由于实验测试离散性比较大,长期以来并未受到足够重视.论文采用Kelvin十四面体模型构建出不同相对密度的闭孔泡沫铝三维细观模型并进行单轴压缩数值计算.结果表明,随着轴向应变的增加,泡沫铝塑性泊松比—轴向应变曲线呈倒S形,存在峰值和极小值;泡沫铝塑性泊松比曲线的极小值对应的轴向应变为泡沫铝的密实应变;随着相对密度的提高,泡沫铝的平均塑性泊松比增大.当闭孔泡沫铝的相对密度低于0.1时,其平均塑性泊松比接近于零;当闭孔泡沫铝相对密度大于0.1时,其平均塑性泊松比随相对密度的增加而呈线性从0.17增加到0.5.Of all the parameters that characterizing the mechanical properties of closed-cell aluminum foam （CCAF） ,the plastic Poisson＇s ratio is an important one. In this study,based on Kelvin model,a three- dimensional mesoscopic model of CCAFs is established. Plastic Poisson＇s ratios of the CCAFs with differ- ent relative densities under uniaxial quasi-static compression are analyzed numerically. The calculation re sults indicate that the plastic Poisson^s ratio of CCAFs changes like a inverse S shape with increasing axial strain. The average plastic Poisson＇s ratio of CCAFs has a close relationship with its relative density. When the relative density is less than 0.1 ,the average plastic Poisson＇s ratio of CCAFs is very small and can be ignored. When the relative density is larger than 0.1 ,the average plastic Poisson＇s ratio of CCAFs shows a linear increase with the increase of the relative densities and grows from 0.17 to 0.5.

关 键 词：相对密度 细观模型 单轴压缩 塑性泊松比 变形模式 

分 类 号：O344.1[理学—固体力学]