带有初始缺陷的船体结构极限强度研究

Ultimate strength of hull structure with initial defect

船体结构的初始缺陷主要有初始挠度和焊接残余应力,初始缺陷对于船体的极限强度有着重要的影响。针对目前初始缺陷的模拟较为复杂的问题,寻找一种初始缺陷的简化模拟方法,采用板弯曲理论反推并模拟初始挠度,运用基于固有应变的等效载荷法模拟焊接残余应力,在此基础上应用非线性有限元法建立计及初始缺陷的船体极限强度分析方法。计算结果表明,船体结构初始缺陷对船体结构的影响不可忽略,基于固有应变的等效载荷法可较好模拟焊接缺陷。

The initial deflection and welding residual stress are the two mainly initial defects of the hull structure. Initial defect has an important implication for the ultimate strength of the hull. For the current issues of the simulation of the Initial defect. In this paper, a simplified simulation of an initial defect is proposed; the plate bending theory is used to thrust on the opposite side to simulate the initial defects. The equivalent load method based on inherent strain is used to simulate welding residual stress. On the foundation, the nonlinear finite element method is used to analysis the ultimate strength of the hull with considering the initial defects. The results show that based on the equivalent load inherent strain method can simulate weld defects and the initial defects impacts on the structure of the hull cannot be ignored.