论文部分内容阅读
本文着重研究多级法低周疲劳试验时的应变顺序效性,发现所研究的钢均有明显的应变顺序效应,即增幅与减幅应变顺序时所得到的循环σ-ε曲线有明显差异。减幅应变顺序时钢的循环σ-ε行为更为充分,其循环σ-ε曲线更接近正规试验时所得到的基本循环σ-ε曲线。40Cr钢显示循环软化,1Cr18Ni9Ti钢显示循环硬化。当金属不存在循环稳定化“饱和”状态时,选取半寿命环作为稳定滞后环比较合理。从能量观点分析和研究金属的循环σ-ε行为可能是一条合理而有效的途径。本文用循环滞后能初步分析了所得试验数据。
This paper focuses on the strain order validity of the multi-stage low-cycle fatigue test. It is found that the steel under study has obvious sequence effect of strain, that is, there is a significant difference between the cyclic sigma-ε curves obtained when the amplitudes and the strains are decreasing. The cyclic σ-ε behavior of the steel is more adequate in the decreasing strain sequence, and its cyclic σ-ε curve is closer to the σ-ε curve obtained in the normal test. 40Cr steel shows cyclic softening, 1Cr18Ni9Ti steel shows cyclic hardening. When the metal does not exist in a cyclostationary “saturated” state, it is reasonable to choose a semi-life ring as a stable hysteresis loop. Analyzing and studying the cyclic σ-ε behavior of metals from the energy point of view may be a reasonable and effective way. In this paper, the experimental data can be preliminary analyzed by the cycle lag.