船舶面对波浪冲击问题时,蒸汽管路的结构有可能出现裂纹,进而威胁船舶生命力和可靠性。本文根据某型船舶典型蒸汽管段的结构特点进行物理建模。研究了在45°、90°和180°航向角的海浪冲下的蒸汽管段的应力响应和位移响应。基于有限元数值模拟结果,确定了波浪冲击载荷下船舶蒸汽管段 结构的薄弱环节,即应力集中区域,最终基于Paris公式计算出蒸汽管段运行期内裂纹尺寸的变化情况。结果表明：在45°、90°和180°航向角的海浪冲下蒸汽管段的响应分布规律相似,其中90°航向角y向冲击时管路有最大等效应力和位移分别为为174.84MPa,和15.19mm。且危险点位置几乎均出现在管段弯头处,所有区域的Von-Mises应力值均未出现大于材料屈服极限值的情况。90°航向角的y向冲击,会导致管路的初始裂纹发生扩展,且运行20年时,管道裂纹的长度值为1.85mm。

When ships face wave impact problems, cracks may appear in the structure of the steam pipeline, which poses a threat to the vitality and reliability of the ship. This article conducts physical modeling based on the structural characteristics of a typical steam pipe section of a certain type of ship. Studied the stress and displacement responses of steam pipe sections under wave impact at heading angles of 45 °, 90 °, and 180 °. Based on the results of finite element numerical simulation, the weak link of the ship"s steam pipe section structure under wave impact load, namely the stress concentration area, was determined. Finally, the change in crack size of the steam pipe section during its service life was calculated using the Paris formula. The results show that the response distribution of the steam pipeline section under waves at 45 °, 90 °, and 180 ° heading angles is similar, with the maximum equivalent stress and displacement of the pipeline under y-direction impact at 90 ° heading angle being 174.84MPa and 15.19mm, respectively. And the dangerous points almost all appear at the elbow of the pipe section, and the Von Mises stress values in all areas do not exceed the material yield limit value. The y-direction impact at a 90 ° heading angle will cause the initial crack of the pipeline to propagate, and the length value of the pipeline crack is 1.85mm after 20 years of operation.

TK225