点蚀、裂纹损伤对船用加筋板剩余极限强度的影响

摘要

[目的]长期服役于恶劣海洋环境中的船舶与海洋工程结构,不可避免地会产生裂纹和点蚀,这些损伤会对结构的极限承载能力产生较大影响.为探讨裂纹、点蚀同时存在时对结构承载能力的影响,[方法]采用非线性有限元法开展含裂纹、点蚀损伤的加筋板在轴向压载作用下的极限强度研究.在讨论网格尺寸对含裂纹、点蚀损伤加筋板极限强度影响的基础上,开展裂纹点蚀坑相对位置、点蚀数目、裂纹长度对含裂纹、点蚀损伤加筋板剩余极限强度的影响.[结果]计算结果表明,裂纹长度、点蚀的增加会使加筋板的剩余极限强度下降明显.[结论]这些结果可用于指导全寿期船舶与海洋工程结构的设计与维护.%[Objectives]Ships and offshore platforms serve in the harsh sea environment for a long time. Cracks and pitting corrosion will occur in such a structure and the damage will affect its ultimate strength. [Methods]To investigate the influence of cracks and pitting corrosion on ultimate bearing capacity,the ultimate strength of a structure under axial compression is studied by using a nonlinear finite element.The mesh size of a stiffened plate with cracks and pitting corrosion is first discussed.Then the influence of the relative positions of cracks and pitting corrosion,number of corrosion points and crack length impact on the residual ultimate strength of damaged stiffened plates is discussed via a series of calculations. [Results]The results indicate that the increase in crack length and pitting corrosion significantly decreases the ultimate strength of a stiffened plate.[Conclusions]This provides a useful reference for designing and maintaining ships and offshore structures in their life cycles.