冰区海上平台管节点疲劳寿命计算的新方法

A Nes Method for Fatigue Life Calculation of Tubular Joint of Offshore Platform in Ice Region

我国渤海湾的海冰对海上结构物的作用,较波浪的作用尤为重要。海冰作用于近海平台管节点承受的最大应力与海冰的破裂形式密切相关。海冰的破坏形式主要有:挤压、屈曲、弯曲等,过去在计算应力时,只是按照一种破裂形式,本文综合起来同时考虑几种破裂形式。现有规范中,未给出低温冰载荷作用下的海洋结构用钢的疲劳寿命曲线,本文根据石油大学进行低温随机冰载作用下疲劳裂纹扩展试验的结果,给出了疲劳寿命曲线及其参数。文章在上述基础上,提出了管节点疲劳寿命计算的一种新方法。

The influence of ice force acting on offshore vStructure in Bohai Sea area is more serious than that of the sea wave. The maximum stress acting on tubular joint of offshore platform due to sea ice is closely related to the rupture form of sea ice which consists of crushing, bending and buckling etc. In the calculation of stress in this paper* a few number of rupture forms is considered together at same time, while in the past time, only one form is accorded. Moreover, in the present code, no fatigue life of steel structure under low temperature and ice load is given, but in this paper, the fatigue life curve and its parameters are given according to the results of experimental test of fatigure crack development under low temperature and random ice load. Based on above, this paper proposed a new method for fatigue life calculation of tubular joint in platform structure.