考虑自由液面修正对水压力分布影响的FPSO总体强度分析

On FPSO Global Strength Analysis with and without Free Surface Correction of Hydrodynamic Pressure

基于ABS的DLA方法,对超大型浮式结构物FPSO船体的特征载荷进行长期预报,获得设计波参数,结合SESAM软件进行总体强度分析及载荷工况分析。对水动力荷载进行自由液面修正,采用WSD方法校核修正前后整船屈服屈曲强度。结果表明对动水压采用自由液面修正以后的水压更为贴合实际情况;总体强度满足ABS、方法要求;修正前后差别较小,水线面附近结构强度需要采用局部压载组合校核。通过总体强度分析可以整体观察船体在波浪载荷作用下的应力变形情况,为船体局部特殊结构疲劳子模型计算提供边界位移,并根据利用率优化结构。

Based on the ABS DLA method,the long term loading prediction for an ultra-large FPSO was carried out to get the design wave parameters and characteristic loads,and global strength analysis and load conditions were also researched. According to Free surface correction and WSD method,the hydrodynamic pressure was corrected and global yielding and buckling strength were assessed and compared. The results proved that the hydrodynamic pressure is more realistic after correction. The global strength fulfills the requirement of ABS WSD method. The structure design near the draft water line should be focused on more attention with local analysis method considering the combination of local tank pressure and sea pressure,especially the structure with higher strength utilization ratio,although the difference is slight before and after correction. The simulation results can be used in the fatigue analysis and local hull structure optimization.