极区船舶冰带构件极限载荷评估

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。本文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100mm×100mm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。

Study on Limit Load Assessment for Ice Belt Structure of Polar-Ships

Excessive structure reinforcement may be required under elastic design method for polar-ships. The structure would be reduced significantly, if limit load criteria, which was proposed in other fields, was adopted considering the bearing capacity of structure during plastic stage. This paper takes a 20000 ton PC5 polar multi-purpose transport ship which has been developed by MARIC as the target ship. Nonlinear finite element analysis of the ice belt structure is carried out based on the requirements of the IACS URI specification for ice load and corresponding calculation conditions. According to the FEA results, 100mm×100mm was thought to be a suitable mesh size and elastic-perfectly plastic material was recommended for the material definition. Also, different limit load criteria were compared and twice-elastic-slope method was thought to be more applicable for polar-ships. This work may provide a reference for design and strength assessment of polar-ships.