考虑腐蚀作用下的铝合金三体船疲劳强度直接计算分析

Fatigue strength analysis of aluminum alloy trimaran considering corrosion effects

[目的]针对腐蚀环境下铝合金三体船的疲劳强度进行评估。[方法]以某120 m铝合金三体船为例,基于Miner线性累积损伤理论,运用直接计算法——谱分析法进行三体船疲劳寿命计算。同时,建立不同腐蚀模型,探讨不同腐蚀模型对三体船热点疲劳特性的影响。[结果]结果显示:新型腐蚀模型更符合结构的实际腐蚀过程且具有较好的适应性;不同腐蚀模型对铝合金三体船热点的疲劳影响程度与腐蚀年限有关;铝合金三体船在连接桥与主、侧体连接处其抗腐蚀疲劳强度能力较强。[结论]所得结论对考虑腐蚀环境下的三体船疲劳强度评估具有参考意义。

[Objective]This study evaluates the fatigue strength of an aluminum alloy trimaran in a corros-ive environment.[Method]Taking a 120 m aluminum alloy trimaran as an example,the direct calculation method/spectral analysis method is used to calculate its fatigue life based on Miner's linear cumulative dam-age theory.At the same time,four types of corrosion model are established to compare the hot spot fatigue strength calculation results under different corrosion models and explore the effects of corrosion on the fatigue life of the trimaran.[Results]The results show that the new corrosion model is closer to the actual corro-sion process.The effects of different corrosion models on the hot spots of the aluminum alloy trimaran are re-lated to corrosion years,and the fatigue strength of the connection between the cross-deck and the main and side bodies is strong.[Conclusion]The results of this study have reference significance for the fatigue as-sessment of trimarans in corrosive environments.