疲劳失效准则在钛合金BT9低周rn疲劳寿命估算中的应用

摘要

Strain controlled low-cycle fatigue tests of titanium alloy BT9 under pull-push, torsion and combined axial and torsional proportional loading were carried out. The experimental data of the titanium alloy BT9 were obtained. Several criteria of lifetime prediction and their precision were discussed. A modification of the generalized fatigue criterion of Makinde-Neale was brought forward based on the analysis of Brown-Miller and Makinde-Neale's theory. The lifetime predictions were conducted by using the modification for titanium alloy BT9 under multiaxial strain conditions. The predicted results are in good agreement with experimental results.%在应变控制条件下对钛合金BT9进行了单轴 拉-压、纯扭及拉-压与扭转比例加载的低周疲劳试验，得到了相应的试验结果。讨论了几 种寿命预测准则及其寿命预测精度。在分析Brown-Miller理论及Makinde-Neale广义疲劳 失效准则的基础上，提出了Makinde-Neale广义疲劳失效准则的变异方程。应用所提出的方 程对钛合金BT9进行了多轴应变条件下的寿命预测，并得出了更为符合试验结果的预测结果 。