FPSO甲板贯穿圆管角焊缝焊根疲劳

Fillet Weld Root Fatigue Failure for FPSO Tubular Penetration Joints on Main Deck

对浮式生产储油卸油装置(FPSO)甲板贯穿圆管角焊缝焊根疲劳进行研究。针对传统焊根疲劳工程剪应力计算方法的局限性,提出一种焊喉截面等效剪应力法,借助有限元手段、临界面应力矢量转换与结构应力法联合计算,完成对角焊缝45°焊喉截面等效应力的提取,归纳出适于工程应用的焊根疲劳应力集中系数参数化方程。对某实船FPSO主甲板上典型的贯穿圆管节点进行焊根疲劳预报,得出满足疲劳设计要求的最小焊喉推荐尺寸,计算结果相比采用传统方法所得结果更加准确合理,计算公式适于工程应用。

Study for the fillet weld root fatigue performance of FPSO tubular inserted joints on main deck.Aiming at the limitation of traditional "engineering shear stress" method, stress vector converting on given critical plane and structural stress method are employed to extract the equivalent stress components on 45degree throat section in way of finite element analysis;Parametric analysis is performed for geometry parameters and weld root stress concentration factors, normalized equations are derived. Weld root fatigue prediction is performed for typical tubular penetration joint using new method and traditional method, the minimum weld leg scantling is calculated. Compared with the traditional method, the calculation results are more accurate and reasonable, and the calculation formula is suitable for engineering application.