点蚀损伤船体结构板的极限剪切屈曲强度研究

Ultimate shear strength of ship structural plate with pitting corrosion damnification

腐蚀损伤导致船体结构板的极限承载能力大幅度下降。文章采用腐蚀体积描述板的点蚀损伤程度,模拟船体结构板的点蚀损伤形态,在点蚀损伤板模型中变化板的厚度、点蚀数目、点蚀直径以及点蚀分布等要素,实施系列有限元数值模拟计算,在进行理论分析的基础上,采用统计学方法,建立了点蚀损伤板极限剪切屈曲强度的评估方法,得到了点蚀损伤板极限剪切屈曲强度的计算公式。从而确立了基于腐蚀体积的点蚀损伤船体结构板极限剪切屈曲强度的评价技术,可为在役海船点蚀损伤后的安全性评估提供有效的技术手段。

Corrosion-caused thickness loss makes the ultimate strength of ship structural plates degraded significantly. An assessing method for ultimate strength of ship hull plate with corrosion damnification un- der edge shear loading based on corroded volume loss is proposed by theoretical deduction and finite ele- ment analysis. The models which are in accord with the actual ship hull plate are obtained. The quantita- tive assessment formulae are obtained by statistics approach according to the data that come from the non- linear finite element analyses of a series of the setting models by changing the plate thickness, the number, the diameter and the distribution of the pits. It is found out that the proposed corroded volume loss based ultimate strength assessment formulae can accurately predict the uhimate buckling strength of the pitted plate under the shear loading. Moreover, the formulae are applicable for reliability or risk assessment of the actual ship panels with pitting corrosion wastage of the sea-going steel ships during their service lives.