船舶舱口角隅疲劳强度及热点应力研究

舱口角隅部分的疲劳问题是疲劳分析的重要内容.本文建立了某船的全船有限元模型并分别采用嵌入式模型和外部模型对舱口角隅进行细化.比较不同的单元类型、热点应力选取方式对疲劳损伤的影响.同时采用直接计算的谱分析方法计算了舱口角隅的疲劳损伤.发现当选用最大主应力作为热点应力时实体单元计算结果较壳单元偏小.同一类型单元节点数目的不同对损伤结果影响不大.热点应力选取方式对疲劳损伤的计算影响较大,在对舱口角隅疲劳强度进行分析时建议选用最大主应力插值的方式计算热点应力.

Research on fatigue strength and hotspot stress of ship hatch corner

The fatigue problem of hatch corner is an important content of fatigue analysis.In this paper,the finite element model of a ship is established and the hatch corner is refined with embedded model and external model.The effects of different types of elements and hot spot stress on fatigue damage are compared.At the same time,the fatigue damage of hatch corner are calculated by the spectral analysis method of direct calculation.The calculation result of the solid element is smaller than the shell element when the maximum principal stress is used as the hot spot stress.The difference of the number of nodes in the same element type has little effect on the result of damage.Fatigue damage is affected by hot spot stress selection method.The calculation of hot spot stress by the method of maximum principal stress interpolation is proposed in the analysis of fatigue strength of hatch corner.