泡沫铝硅合金动态压缩力学性能及吸能特性研究

利用分离式霍普金森压杆研究了泡沫铝硅合金的动态压缩力学性能，得到了应变率为1400s-1~2500s-1的动态应力-应变曲线，且与准静态压缩实验结果进行了对比，分析了应变率对泡沫铝硅材料压缩强度和吸能特性的影响。动态压缩实验过程中，针对泡沫铝硅合金的低阻抗特点，采用LC4铝压杆和半导体应变片改进了测试装置和方法，保证了实验结果的可靠性。结果表明:应变率对泡沫铝硅合金的流动应力有着明显的影响，其流动应力随着应变率的增大而增大；由于惯性效应和胞孔的坍塌，在弹性极限处应力出现波动，且波动应力随应变率的增大而增大。该文还讨论了泡沫铝硅合金在不同应变率下的吸能效率。

INVESTIGATION ON THE DYNAMIC COMPRESSIVE BEHAVIOR AND ENERGY ABSORPTION PROPERTIES OF ALUMINIUM-SILICON FOAM

The dynamic mechanical properties of aluminum-silicon foams were investigated by using a spit Hopkinson pressure bar (SHPB), the dynamic stress-strain curves were obtained at strain rates ranging from 1400s-1 to 2500s-1, and compared with the quasi-static compressive results, the effect of the strain rate on the compressive strength and absorption efficiency was analyzed. During the experiment, according to the low impedance of aluminum-silicon foams, a LC4 aluminum alloy pressure bar and a semiconductor strain gauge were employed to ensure the reliability of the experimental results. The results showed that: the strain rate has an obvious effect on the flow stress of the aluminum-silicon foam, the flow stress increases with the increase of the strain rate; there is an oscillation in flow stress during elastic limitation due to inertia efficiency and collapse of the cells, and the oscillation stress increases with increasing strain rate. The energy absorption efficiency of the aluminum silicon foam at various strain rates was also discussed.