应变率对C_f/Al金属基复合材料力学性能的影响

Effect of Strain Rate on Mechanical Behavior of C_f/Al Composites

利用自行研制的冲击拉伸试验装置对单向碳纤维增强铝基复合材料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 10 0 0 s- 1 应变率范围内完整的应力应变曲线。试验结果表明 Cf/ Al是一种应变率敏感材料 ,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。根据材料在不同应变率下的试验结果 ,提出了应变率强化效应的复合丝束统计本构模型 ,模型分析表明由于复合材料的破坏受多种因素的影响 ,Cf/ Al复合丝的强度不再服从单 Weibull模型 ,用双 Weibull模型更能反映 Cf/ Al复合丝强度的统计分布规律 ,且模型拟合的结果与试验结果吻合得很好。

Tensile impact tests of C f/Al metal matrix composite were carried out by a self designed tensile impact apparatus The stress/strain curves of composites in strain rate range from 0 001s 1 to 1300s 1 were obtained The experimental results indicate that the C f/Al composite is a rate sensitive material, namely the strength, failure strain and residual strength of composite all are depending on strain rate According to the statistical analysis and models, mechanical parameters for the composites and their relationship with strain rate are obtained from experimental results The simulated stress/strain curves from the model are in good agreement with the test data