漆 涛，黄小平，稽春燕，李良碧

(1. 上海交通大学 高新船舶与深海开发装备协同创新中心，上海 200240; 2. 江苏科技大学 船舶与海洋工程学院，江苏 镇江 200135)

基于谱分析法的超大型浮体疲劳强度分析

漆 涛1，黄小平2，稽春燕2，李良碧2

(1. 上海交通大学 高新船舶与深海开发装备协同创新中心，上海 200240; 2. 江苏科技大学 船舶与海洋工程学院，江苏 镇江 200135)

运用ANSYS/AQWA对某超大型浮体平台进行水动力响应计算和结构响应分析，在此基础上选择3个典型疲劳热点区域建立有限元子模型，求出各区域的热点应力传递函数。依据谱分析法的疲劳计算流程对危险节点进行疲劳分析，计算疲劳损伤和寿命。分析结果表明，横浪时对平台造成的疲劳损伤最大。横撑与下浮体围壁连接处以及立柱外壳与上箱体底板连接处这两处的疲劳寿命不满足设计要求。建议对该结构连接处进行改进或重新设计。

ANSYS/AQWA；超大型浮体；热点应力；疲劳损伤；谱分析法

Abstract: Hydrodynamic response of a VLFS was calculated by means of ANSYS/AQWA. Then FEA sub-models of three chosen key spot areas were built to obtain the stresses transfer function of these hot spots. Spectral-based method for fatigue analysis was used for the fatigue analysis of the key spots, including calculation of their cumulative fatigue damage and fatigue life. The analysis results show that the transverse wave, in general, may result in the most significant damage on the platform. And it is found that two spots, respectively located in connection parts between cross brace and floating body as well as connection parts between columns and upper box, may not satisfy the requirement of design fatigue life. Therefore, further modification or redesign is needed on these parts.

Keywords: ANSYS/AQWA; VLFS; hot spots stress; fatigue damage; spectral-based method

超大型浮体平台(Very Large Floating Structure，简称VLFS)是指长、宽具有千米数量级、而高度为数米或数十米的钢性浮体结构，是一种新型的海上结构物。常见的超大型浮体形式有箱型，半潜柱式型等。其中半潜柱式型浮体的构造比较复杂，但其水动力性能较好，适宜用在较恶劣的海洋环境中。

超大型浮体长期受到波浪载荷等恶劣海况作用，引起交变应力导致结构疲劳破坏，是其重要破坏形式。本文研究的海上超大型浮式结构物(以下简称超大浮体)为半潜柱式浮体构造，其体型庞大，结构复杂，通常由8～12个单模块组成。……