高应变率下S30408不锈钢的动态力学性能及拉压不对称性研究

STUDY ON DYNAMIC MECHANICAL BEHAVIOR AND TENSION-COMPRESSION ASYMMETRY OF S30408 STAINLESS STEEL UNDER HIGH STRAIN RATE

  • 摘要: 为研究S30408不锈钢的动态力学性能及拉压不对称性,采用霍普金森拉杆(SHTB)和压杆(SHPB)装置对其开展了3种应变率(1000 s−1、3000 s−1、5000 s−1)动态冲击试验,并进行了静态拉伸和压缩试验,获得了S30408不锈钢在不同条件下的应力-应变曲线。通过分析发现:S30408不锈钢具有明显的应变率强化效应,在静态条件下S30408不锈钢存在一定的拉压不对称性,在高应变率条件下会放大这种特性,S30408不锈钢压缩时的塑性应力明显大于拉伸时的塑性应力。基于试验结果,建立了拉伸和压缩条件下修正后的Johnson-Cook模型,修正后的模型可较好反映S30408不锈钢的动态力学性能,可为冲击、爆炸等高应变率下的S30408不锈钢力学性能研究提供参考。

     

    Abstract: To investigate the dynamic mechanical properties and tensile-compression asymmetry of S30408 stainless steel, dynamic impact tests were carried out on stainless steel at three strain rates (1000 s−1、3000 s−1、5000 s−1) using Hopkinson tensile (SHTB) and pressure bar (SHPB) device, and static tensile and compression tests were carried out. The stress-strain curves of S30408 stainless steel under different conditions were obtained, and the analysis revealed that S30408 stainless steel has an obvious strain rate strengthening effect. There is a certain tensile-compression asymmetry in S30408 stainless steel under static conditions, which will be amplified under high strain rate conditions, and the plastic stress in S30408 stainless steel in compression is significantly larger than that in tension. Based on the experimental results, a modified Johnson-Cook model was established for tensile and compressive conditions, which can better reflect the dynamic mechanical properties of S30408 stainless steel and can provide a reference for the study of the mechanical properties of S30408 under high strain rates such as impact and explosion.

     

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