破损船体非对称弯曲极限强度分析及可靠性评估

Ultimate Strength Analysis and Reliability Assessment of Damaged Ship Hulls in Unsymmetrical Bending

在船体发生破损后 ,其剩余有效剖面是非对称的 ,船体还可能倾斜。本文首先对破损船体非对称弯曲进行了弹性和塑性分析 ,在此基础上假设了破损船体发生整体破坏时的剖面应力分布 ,给出了破损船体非对称弯曲极限强度分析方法 ,并采用了比较精细的方法计算加筋板格的屈曲极限强度。以箱型梁模型和超大型油船为例 ,将本文的计算结果与试验、ISUM法及解析公式的结果进行了比较。基于破损船体极限强度 ,结合重要性样本法 ,对 65 ,0 0 0 t散货船在完整和破损状态下的船体结构安全性进行了评估 。

After a ship hull is damaged, the residual resisting section will be unsymmetrical and the hull may be heeled also. Based on the detailed elastic and plastic analysis of the damaged ship hull in unsymmetrical bending, this paper assumes a stress distribution of the damaged hull section and proposes a method to analyze the ultimate strength of the damaged ship hull in unsymmetrical bending. A fine method to calculate the ultimate compressive strength of stiffened panels is also adopted. Comparisons with results of test, ISUM and analytical formulae of box girder models and VLCCs are performed. Based on the ultimate strength of the damaged ship hull, the structural safety of a 65,000t bulk carrier in contact and damaged conditions is assessed using important sampling method and some useful conclusions are drawn.