新型钛合金保载疲劳裂纹扩展行为预报方法研究

Prediction Method of Dwell-Fatigue Crack Growth Behavior of New Titanium Alloy

本文对新型钛合金的保载疲劳裂纹扩展行为进行了试验研究。该新型钛合金主要被用于深海载人潜水器的压力壳,试验获得不同温度下载荷比R=0.3和不同波形下载荷比R=0.03时的保载疲劳裂纹扩展速率。基于已有的钛合金保载疲劳裂纹扩展预报模型,对不同温度和不同波形下的保载疲劳裂纹扩展速率进行了预报。结果表明,本文所选择的预报模型可用于新型钛合金的保载疲劳裂纹扩展行为的预报,能够准确预报不同温度下保载疲劳裂纹扩展速率,修正后也能准确预报不同波形下的静疲劳裂纹扩展速率。

This paper presents the test of the dwell-fatigue crack growth behavior of a new titanium alloy for the pressure shell of deep-sea manned submersibles.The dwell-fatigue crack growth rate at load ratio R=0.3 with different temperatures,and load ratio R=0.03 with different waveforms were obtained.Based on the existing titanium alloy dwell-fatigue crack growth prediction model,the dwell-fatigue crack growth rate under different temperatures and waveforms was predicted.The results show that the prediction model selected in this paper can be applied for prediction of the dwell-fatigue crack growth behavior of new titanium alloys,and it can accurately predict the dwell-fatigue crack growth rate at different temperatures.After correction,it can also accurately predict the dwell-fatigue crack growth rate under different waveforms.