基于疲劳强度谱分析的火炬塔支撑结构设计

火炬塔是FPSO上主要装置之一,火炬塔支撑结构的疲劳强度是结构设计重点关注的对象。在介绍疲劳谱分析方法及BV-Homer软件的基础上,总结整理出基于该软件的疲劳谱分析的基本流程,利用BV-Homer软件对火炬塔支撑结构原设计方案的疲劳损伤进行了分析校核,根据计算结果对支撑结构设计方案进行了修改。研究表明：原设计方案的疲劳强度不满足规范要求,修改方案的疲劳寿命大幅提高,满足规范要求；火炬塔支撑外侧主管及外侧热点的疲劳损伤较大,设计时需要重点关注；增加肘板、热点区域结构板厚是提高疲劳强度的有效方式；基于谱疲劳分析的结构疲劳强度分析方法可应用于其他类似结构。

Structure Design of Flare Tower Supports Based onSpectral Fatigue Analysis

The flare tower is a necessary structure for FPSO. Designer should pay more sttention to the fatigue strength of flare tower supports in the detail design phase. The spectral analysis methodology and the software BV-Homer are introduced firstly. The spectral fatigue analysis approach on flare tower supports is detailed. And then the fatigue cumulative damage of preliminary structure design is calculated and checked according to BV rules. Reinforcements are implemented on the supporting structure based on the results of spectral fatigue analysis. It is showed by the study that the fatigue strength of modified structures is superior to the preliminary structures and satisfies BV rules. The outer tube and the outer hot spot should be attached more importance. Adding the bracket with soft toes and increase thickness of hot spot local plate are most effective way to improve the fatigue strength. The design methodology based on spectral analysis can be adapted to the other similar offshore structures.