铝合金6061-T6高速切削物理仿真材料本构模型

摘要

The quasi-static and dynamic mechanical properties experiment of Al6061 - T6 in high temperature (20 ~ 500℃ ) and high strain rate (up to 104/s) was carried out on the quasi-static press and split Hopkinson press bar ( SHPB ) equipment. Then the effect curves of strain hardening, strain rate strengthening and thermal softening were obtained. According to these curves, the classic JC ( Johnson-Cook) equation was modified. Furthermore, the modified JC equation was validated in the high speed cutting physical simulation model. The results showed that the Al6061 - T6 flow stress increased with the increasing of strain and strain rate, and obviously decreased with the increasing of deformation temperature. The description accuracy of the modified JC equation was higher than the JC equation. The obtained Al6061 - T6 constitutive equation can provide important material parameters for physical simulation models of its high speed machining process.%在分离式Hopkinson压杆实验(SHPB)和准静态压缩实验装置上对铝合金6061-T6进行了高温(20～ 500℃)高应变率(达104/s)下的动、静态力学性能实验,在获得应变强化、应变率强化和热软化效应曲线的基础上,修正了经典的JC(Johnson-Cook)方程,并在仿真模型中验证了所得MJC方程的有效性.研究表明:铝合金6061-T6材料流变应力随应变和应变率的升高而升高,随变形温度升高而降低；提出的JC修正方程较JC方程具有更高的本构关系描述精度；所获得的铝合金6061-T6材料本构方程,为该材料高速切削物理仿真提供了精确的 动、静态材料模型参数.