【摘要】 文章在改进的McEvily疲劳裂纹扩展速率模型的基础上,提出了室温下钛合金保载-疲劳裂纹扩展速率预报公式。分析公式中应力比、保载时间、保载—疲劳循环最大应力对裂纹扩展速率的敏感性;利用该公式对钛合金Ti-6242的疲劳和保载—疲劳裂纹扩展速率进行预报,并与相应试验结果进行对比分析。结果显示:该预报公式对载荷循环中最大应力最为敏感,保载—疲劳裂纹扩展速率随最大应力呈指数增加;通过与试验对比,该公式对保载—疲劳裂纹扩展具有良好的预报能力。更多还原

【Abstract】 The prediction method for the dwell-fatigue crack growth for titanium alloys is presented based on the improved McEvily model. The sensitivity analysis of influential parameters in this relation is carried on the stress ratio, dwell period and the maximum stress, which shows that the prediction results are more sensitive to the maximum stress and the dwell-fatigue crack growth rate exponentially increases with the maximum stress. Furthermore, the dwell-fatigue crack growth rate of the titanium alloy Ti-6242 under constant amplitude loading is predicted using the relation, and compared with the test data. The good agreement between test data and prediction results validates the reasonability of the model.更多还原