柔性管节点对海洋导管架固定平台非线性分析的影响

Influence of flexible tubular joints on nonlinear analysis of offshore jacket fixed platform

引入MSL非线性柔性管节点模型,研究了柔性管节点对导管架固定平台非线性分析的影响。首先对单一管节点进行静力加载的非线性分析,研究管节点柔性特征对自身非线性静力分析的直接影响;然后对二维框架结构系统进行静态非线性倒塌分析,研究柔性管节点对结构系统静力非线性分析的影响;最后对某实际三维导管架平台模型进行模态分析及非线性地震时程分析,以研究柔性管节点对平台整体结构系统动态分析的影响。研究表明,考虑柔性管节点进行海洋导管架固定平台非线性分析时,固定平台的局部和整体刚度均得到了显著的降低,进而影响了非线性强度分析结果及平台设计的经济性,因此建议使用MSL公式。

MSL nonlinear flexible tubular joint model is introduced to study the influence of flexible tubular joints on the nonlinear analysis of the jacket platform is studied herein. Firstly, nonlinear analysis of static load on a single tubular joint is carried out to study the direct influence of the flexibility characteristics on its own nonlinear static analysis;and then static nonlinear collapse analysis of a two-dimensional frame structure system is made to study the influence of the flexibility characteristics of tubular joints on the static nonlinear analysis of two-dimensional structural system;and finally modal analysis and nonlinear seismic time-history analysis are performed on an actual three-dimensional jacket platform model to study the influence of flexible tubular joints on the dynamic analysis of the overall structural system of the platform. The study indicates that, when flexible tubular joints are taken into consideration in the nonlinear analysis of the offshore jacket platform, the local and overall stiffness of the platform show significant reduction, which further affects the results of the nonlinear strength analysis and the economy of the platform design. Therefore, the use of MSL formula is recommended.