6061铝合金的动态拉伸性能及其本构模型

摘要

在0.08,35,110,210,550 s-1的应变速率下对6061铝合金进行单轴拉伸试验,对其动态拉伸性能进行研究,得到不同应变速率下的真应力-真应变曲线;基于Johnson-Cook本构模型,建立该铝合金的塑性变形本构模型,并对该模型进行了验证.结果表明:随着应变速率增加,6061铝合金的屈服强度增大,断后伸长率降低,但其断裂强度则未发生明显变化;建立的本构模型能够很好地描述6061铝合金在塑性变形过程中流变应力的变化.%The dynamic tensile properties of 6061 aluminum alloy was studied by the uniaxial tensile experiment at strain rates of 0.08,35,110,210,550 s-1.The trure stress-ture strain curves were obtained at different strain rates.A plastic deformation constitutive model of the aluminum alloy was established based on the Johnson-Cook model, and the model was verified.The results show that, with the increase of strain rate, yield strength of 6061 aluminum alloy increased and elongation after fracuture decreased, but its fracture strength had not obvious changes.The constitutive model can describe well the change of flow stress of 6061 aluminum alloy during plastic deformation.