深海载人潜水器作业过程中，耐压壳结构承受下潜（载荷增加）、巡航（上峰值保载）、上浮（载荷降低）、休整阶段（下峰值保载）和再次下潜的循环载荷作用。因此，针对潜水器用钛合金材料开展了疲劳、上峰值保载-疲劳（巡航）和上-下峰值保载-疲劳（巡航-休整）裂纹扩展速率试验研究。试验结果表明，钛合金上峰值保载-疲劳裂纹扩展速率高于疲劳裂纹扩展速率，并随着上峰保载时间的增加，上峰值保载-疲劳裂纹扩展速率越高；随着下峰值保载时间的引入，使得上-下峰值保载-疲劳裂纹扩展速率明显高于上峰值保载-疲劳裂纹扩展速率，并且裂纹扩展速率随着下峰值保载时间的增加而不断加快。
During the service of deep-ocean manned submersible, the pressure shell in each operation bears loads as follows: diving stage (load increase), cruising state (upper peak load holding), floating stage (load decrease), rest stage (lower peak load holding). Therefore, this paper carried out the experimental study on the influence of upper peak load holding (cruising state) and upper-lower peak load holding (cruise-rest state) on the fatigue crack growth tests of new titanium alloy. The results show that the dwell-fatigue crack growth life under upper peak load holding is faster than the fatigue crack growth life, and the dwell-fatigue crack growth life of under upper-lower peak load holding is faster than the dwell-fatigue crack growth life under upper peak load holding. With the increase of the lower peak load holding time, the dwell-fatigue crack growth rate also increases.
2022,44(14): 26-29 收稿日期：2021-03-06
DOI：10.3404/j.issn.1672-7649.2022.14.006
分类号：U663.1
基金项目：国家自然科学基金资助项目（51709134）；国家重点研发计划项目（P2016YFC03007603-02）；江苏省自然科学基金资助项目（BK20160559，BK20170575）
作者简介：王珂(1979-)，女，副教授，主要从事船舶与海洋结构物制造力学研究
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