中文摘要：

5083铝合金材料在工程领域应用广泛，会受到包括冲击和碰撞等多种不同情况的强动加载，亟需对其宽应变率加载下的力学性能及其本构模型开展研究。首先，对5083铝合金进行了系统的准静态实验及中、高应变率加载下的拉伸和压缩实验，得到了宽应变率加载下的应力一应变曲线。实验结果表明，该材料在同一实验条件下所得到的应力一应变曲线，其强化阶段的拉伸曲线总是低于压缩曲线，并从微观机制上对这一现象进行了合理解释。然后，通过引入损伤，考虑了损伤对该材料拉伸加载情况下的力学性能影响。基于连续介质力学及其实验结果，获得了损伤演化方程。最后，借助改进的Johnson—Cook（JC）本构模型，并基于已确定的损伤演化方程，得到了考虑损伤的5083铝合金本构模型。通过实验曲线与所得模型曲线的对比，吻合良好，表明该模拟具有很好的适用性，能够对该材料的工程应用提供有效的科学依据、分析模型和必要的参考。

英文摘要：

The 5083 aluminum alloy is widely used in engineering,and is inevitably subjected to a variety of different loadings,including strong dynamic loading such as impact and collision. Therefore it is necessary to study its mechanical properties under loading of a wide range of strain rates as well as its constitutive model. With this in view,firstly,an experimental study of the 5083 aluminum alloy was carried out at quasi-static, middle and high strain rates of tension and compression loading and the stress-strain curves of the wide strain rate were obtained. The experimental results show that in the strengthening stage, the tensile stress-strain curves are always lower than the compression stress-strain curves when the experimental condition is kept constant, so the phenomenon is explained by microscopic mechanism. Then, by introducing damage into our study,the effects of damage on the material＇s mechanical properties were considered under impact tensile loading. Based on the continuum mechanics and experimental results, the damage evolution equation was obtained. Finally,by improving the Johnson-Cook （JC） constitutive model and the existing damage evolution equation, the dynamic constitutive model considering the damage of the 5083 aluminum alloy was established. By comparing the experimental curves with the model curves, it was found that their fitting is good, showing that the proposed model has good applicability. Our research can serve as an effective scientific basis, an analytical model and necessary reference for the engineering application of the 5083 aluminum alloy.