极区船舶冰带构件极限载荷评估

Limit Load Assessment for Ice Belt Structure of Polar Ships

弹性设计准则下,极区船舶通常需要过度的结构加强以确保航行安全。若采用极限载荷设计准则,考虑结构的塑性承载能力,利用一部分屈服点之后的强度储备,则能大大减轻结构重量。文章以中国船舶及海洋工程设计研究院(MARIC)研发的某20000吨级PC5级极地多用途运输船为目标船型,基于IACS URI规范关于冰载荷及相应计算工况的要求,进行了非线性有限元分析。基于计算结果,工程计算推荐100 mm×100 mm的网格尺寸,材料定义推荐使用理想弹塑性材料。通过对比不同极限载荷准则,认为两倍弹性斜率准则相对更适用于船舶构件。研究成果可为极区船舶结构的设计与强度验证提供参考。

According to elastic design principles,the excessive structure reinforcement may be required for polar ships to ensure the sailing safety.The structure weight would be reduced significantly if limit load criteria is adopted considering the bearing capacity of structure during plastic stage.Taking a 20 000 ton PC5 polar multi-purpose transport ship developed by MARIC as the target ship type,the nonlinear finite element analysis is carried out based on the requirements of the IACS URI specification for ice load and corresponding calculation conditions.According to the FEA results,mesh size of 100 mm×100 mm is recommended for the engineering calculation,and elastic-perfectly plastic material is recommended for the material definition.Through the comparison of different limit load criteria,the twice-elastic-slope rule is thought to be more applicable for polar ships.The research may provide reference for structural design and strength assessment of polar ships.