2519A铝合金的动态力学性能及本构关系

为研究应变速率及温度对2519A铝合金流变应力的影响，对2519A铝合金进行动态力学性能测试及准静态拉伸实验，结合光学显微镜及透射显微电镜分析应变速率及温度对微观组织演化的影响。研究结果表明：2519A铝合金具有应变速率效应及温度敏感性。采用变量分离与非线性拟合方法对准静态及霍普金森压杆（SHPB）实验数据进行拟合，得到2519A铝合金的Johnson-Cook本构模型参数，曲线拟合与实验结果吻合较好，为力学性能的研究及抗弹性能有限元分析提供了参考。

Dynamic mechanical properties and constitutive equations of 2519A aluminum alloy

To analyze the effects of strain rate and temperature on the flow stress of 2519A aluminum alloy, the dynamic mechanical properties of 2519A aluminum alloy were measured by dynamic impact tests and quasi-static tensile tests. The effects of strain rate and temperature on the microstructure evolution were investigated by optical microscopy （OM） and transmission electron microscopy （TEM）. The experimental results indicate that 2519A aluminum alloy exhibits strain-rate dependence and temperature susceptibility under dynamic impact. The constitutive constants for Johnson--Cook material model were determined by the quasi-static tests and Hopkinson bar experiments using the methods of variable separation and nonlinear fitting. The constitutive equation seems to be consistent with the experimental results, which provides reference for mechanical characteristics and numerical simulation of ballistic performance.