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为考查闭孔泡沫铝材料的静、动态力学性能,运用万能材料实验机及分离式霍布金森压杆(SHPB)系统,对闭孔泡沫铝准静态及动态力学性能进行试验研究。分析密度对泡沫铝准静态力学性能的影响情况,对比准静态与动态条件下闭孔泡沫铝材料力学性能的差异,并讨论泡沫铝动态测试过程中的一些注意事项。结果表明:此种闭孔泡沫铝材料的静、动态应力应变关系曲线均具有明显的弹性段、应力平台段及压实段的3阶段特征。准静态条件下,应力平台随着密度的增大而相应增大;闭孔泡沫铝的动态应力应变关系具有较为明显的应变率效应。动态试验中应变片、数据处理方法及入射波形均会影响泡沫铝动态力学性能的试验结果。泡沫铝孔洞的分批塌陷导致应力应变曲线出现明显波动现象。
In order to test the static and dynamic mechanical properties of closed-cell aluminum foam, the quasi-static and dynamic mechanical properties of closed-cell aluminum foam were investigated by using a universal testing machine and a split-Hopkinson pressure bar (SHPB) system. The influence of density on quasi-static mechanical properties of aluminum foam was analyzed. The difference of mechanical properties of closed-cell aluminum foam was compared under quasi-static and dynamic conditions. Some precautions during the dynamic testing of aluminum foam were discussed. The results show that the static and dynamic stress-strain curves of the closed-cell aluminum foam have obvious three-stage characteristics of elastic section, stress platform section and compaction section. In the quasi-static condition, the stress platform increases with the increase of density, and the dynamic stress-strain relationship of the closed-cell aluminum foam has obvious strain rate effect. In the dynamic test, the strain gauges, data processing methods and incident waveforms all affect the test results of the dynamic mechanical properties of aluminum foam. Batch collapse of foamed aluminum voids leads to significant fluctuations in the stress-strain curve.