应变率对T300/Al(L2)复合丝拉伸性能的影响

Effect of strain rate on tensile behaviour of T300/Al composite wires

利用MTS810试验机和自行研制的冲击拉伸试验装置对T30 0 /Al复合丝实施了不同应变率下的拉伸试验 ,获得了材料从 0 .0 0 1s-1到 130 0s-1应变率范围内完整的应力应变曲线 .结果表明 :T30 0 /Al是一种应变率敏感复合材料 ,随着应变率的提高 ,材料的拉伸强度、失稳应变均相应提高 ,具有明显的应变率强化效应和动态韧性现象 ,这主要是由铝基体的应变率强化效应和应变率历史效应引起的 .根据材料在不同应变率下的试验结果以及对其不同变形阶段机理的分析 ,提出了弹塑性复合丝束模型 ,并由此建立了相应的应变率相关的一维统计损伤本构方程 。

Tensile impact tests of T300/Al metal matrix composite wires have been carried out by a self designed tensile impact apparatus and the quasi static tensile tests have been performed on a MTS-810 testing machine. The stress/strain curves of composites have been obtained at strain rates ranging from 0.001 s -1 to 1 300 s -1 . The experimental results show that the T300/Al composite is a strain rate sensitive material, namely both strength and failure strain of composite depend on strain rate. Based on these experimental results, an elastic plastic coated fiber bundle model and a one dimensional damage constitutive equation for T300/Al composite have been established. The mechanical parameters for composites and their relationships with strain rate are obtained from experimental results. The simulated stress/strain curves from the model are in good agreement with the test data.