基于等效梁的座底式平台立柱强度分析方法

Strength analysis method of submersible platform columns based on equivalent beam

“中油海33”座底式平台操船手册规定最大作业水深10 m,而目标海域水深11 m,超出操船手册限制,采用有限元软件ABAQUS校核其立柱强度。大立柱和中立柱截面复杂,通过ABAQUS分析得到其等效梁属性,以梁单元建立立柱数值模型。由于座底式平台顶部甲板和底部沉垫的抗弯刚度远大于立柱,所有立柱顶部和底部分别采用刚体约束,得到仅有立柱构成的整体模型。计算作业工况和生存工况不同方向环境载荷作用下立柱的动力响应。根据API规范校核结果,得知作业水深11 m时立柱满足作业工况和生存工况的强度要求。本方法利于施加波浪和海流载荷,可以高效确定座底式平台立柱强度状态。

The maximum working depth of"CPOE 33"submersible platform is 10 m and the target water depth is 11 m,which is beyond the limit of the operation manual.The strength of its columns is checked by the finite element software ABAQUS.The sections of large column and middle column are complex.The equivalent beam properties are obtained by ABAQUS analysis,and the column numerical model is established with beam elements.As the bending stiffness of the top deck and the bottom mat of the submersible platform are much greater than that of the columns,the rigid body constraint is applied to the top and the bottom of all columns,and the overall model consisting of only columns is obtained.The dynamic response of the column under different directions of environmental loads is calculated.According to the API specification check results,it is known that the columns meet the strength requirements of the operation condition and the storm survival condition when the working water depth is 11 m.This method is advantageous to apply wave and current loads,and can determine the strength state of the columns of the platform.