基体材料对铝蜂窝动态强化特性的影响

Effect of base materials on the dynamic enhancement of aluminium honeycombs

为了明确基体材料对铝蜂窝动态强化行为的影响,首先从铝蜂窝结构中取出蜂窝壁,制成小试样并对其进行了力学性能测试,然后对几何参数相同而基体材料不同的2种铝蜂窝材料分别进行了单轴面外静态和动态压缩实验。实验结果表明,2种铝蜂窝均存在明显的动态强化现象,但动态强化率存在显著差异。横向惯性理论可以解释蜂窝的动态强化行为和强化率的差异:基体材料应变硬化率高的铝蜂窝,其面外方向的动态强化现象相对更显著。

In order to clarify the influence the base materials have on aluminium honeycombs and to explore the difference of the buckling modes between dynamic and static compression, research of ho- neycombs with different base materials （3003H18 and 5052H18 aluminium alloy） was done. Test on specimens cut from aluminium honeycombs was conducted to investigate the uniaxial tension mechani- cal properties of base materials in this study. Both quasi-static and dynamic experiments on aluminium honeycombs with same geometry but made of different base materials were conducted. The quasi-stat- ic test was performed using universal tester with the loading speed of 0.1 mm/s and an ＂SHPB＂ system with large diameter PMMA bars was adopted in dynamic test with two average impact speeds （10 m/s and 28 m/s）. High speed camera was applied in ＂SHPB＂ test to capture the image of the dy- namic deformation of aluminium honeycomb structure. The test results showed that three stages can be divided in the compression of honeycombs and the buckling modes of different aluminium honey- combs under different loading speeds were the same. Dynamic enhancement existed in two kinds of a- luminium honeycombs but with different enhancement ratios. The dynamic enhancement of 3003H18 honeycombs was more remarkable than that of 5052H18. Inertia theory can explain the enhancement. With the analysis of the result of base-material experiment, consumption was made that Honeycombs with a higher strain hardening rate tend to have a more remarkable enhancement.