铝合金正四面体点阵夹芯材料准静态压缩行为研究

Quasi-Static Compressive Behavior of Tetrahedral Lattice Truss Structures Made from Aluminium

摘要: 本文通过冲压折叠法制造6061铝合金正四面体点阵夹芯芯体结构，采用钎焊连接面板及芯体，研究了相对密度为0.05正四面体点阵夹芯材料在T6、T7及退火三种不同热处理状态下的准静态压缩(初始应变速率为10−3 S−1)行为。研究结果表明：准静态压缩应力应变曲线均表现为三个明显的变形阶段，即线弹性阶段、较长的屈服阶段及致密化阶段，致密化应变为0.4；能量吸收主要发生在芯体剧烈的塑性变形阶段即较长的屈服阶段，吸能量T6态大于T7态，退火态最低；吸能效率由材料的塑性及强度共同决定，吸能效率T7总是大于T6，退火态开始最小，最后处于两者之间。

Abstract: Tetrahedral lattice truss structures have been made by folding perforated 6061 aluminum alloy sheets. Simple air brazing was used to construct sandwich panels with cellular core; relative density was 0.05. The behavior of quasi-static compression (initial strain rate is 10−3 S−1) was studied in the present study, and three kinds of heart-treatment were investigated, which were T6, T7 and anneal. The results showed that: three distinct stages of deformation show in quasi-static compressive stress-strain curves, namely the linear elastic stage, the longer yield stage and the stage of densification, and densification strain is 0.4; energy absorption mainly occurs in the stage of longer yield, in which severe plastic deformations occur, and the energy absorption of T6 is higher than T7, while the anneal is the lowest; energy absorption efficiency is determined by the material plasticity and strength, and the energy absorption efficiency of T7 is greater than T6, while the annealed state is minimum at the beginning, and finally between T6 and T7.