2024Al高温高应变率下动态塑性本构关系的实验研究

运用SHPB装置,文章对2024Al在不同温度和不同应变率条件下的动态力学行为开展了系列的实验研究,基于Johnson-Cook(JC)本构模型,通过实验数据拟合得到了相应的材料模型参量,从而建立了2024Al的动态塑性本构关系。为进一步验证该本构关系,基于有限元方法,对常温下应变率为700s-1的SHPB实验进行了数值模拟,模拟计算结果与实验结果相吻合,表明所得到的模型可以很好地描述该材料在高温高应变率下的动态塑性力学行为。

Dynamic plastic experiments and constitutive model of 2024 aluminum under high temperature and high strain rate

Dynamic mechanical behaviors of 2024Al under high temperature and high strain rate have been studied with the Split Hopkinson Pressure Bar(SHPB) over a wide range of strain rates and temperatures.The parameters based on the Johnson-Cook constitutive model are determined through the experiments.The model curves based on the obtained parameters are agreed with the experiment curves,then the Johnson-Cook constitutive relationship of 2024Al is established.To validate this constitutive relationship,the SHPB simulation by finite element method is carried out.The simulation curves are compared with the experiment curves.The good consistency between them proves that the parameters obtained can well describe the large strain mechanical behavior of 2024Al under high speed deformation.