CAJ | 학술논문

无论是军船还是民船,船体及主要结构构件表面的点腐蚀对于船舶结构强度和安全性都有较大的破坏作用.文中采用系列非线性有限元计算研究了点腐蚀对于低碳钢板极限抗压强度的影响,模型中计及板初始缺陷的影响,详细讨论了板和点腐蚀物理、几何特性的变化对于板极限承载能力的作用.研究发现在众多影响因素中(例如点腐蚀的直径和深度、板的柔度系数等),点腐蚀密集度指标DOP对于板的极限承载能力有主要和直接的影响.此外,在腐蚀环境恶劣的情况下,厚低碳钢板的使用不一定如预期的那样能延长其使用期限.
무론시군선환시민선,선체급주요결구구건표면적점부식대우선박결구강도화안전성도유교대적파배작용.문중채용계렬비선성유한원계산연구료점부식대우저탄강판겁한항압강도적영향,모형중계급판초시결함적영향,상세토론료판화점부식물리、궤하특성적변화대우판겁한승재능력적작용.연구발현재음다영향인소중(례여점부식적직경화심도、판적유도계수등),점부식밀집도지표DOP대우판적겁한승재능력유주요화직접적영향.차외,재부식배경악렬적정황하,후저탄강판적사용불일정여예기적나양능연장기사용기한.
Pitting corrosion of the steel plates forming the hull and other major structural components of both commercial and naval ships can have a very considerable deteriorating effect on ship struc-tural safety. In this paper, a series of nonlinear FEM analysis is carried out to investigate the effects of pits on ultimate compressive strength of plates,where main influential factors of both plates and pits are studied in detail. The results show that the intensity of pits denoted by DOP (the ratio percentage of the corroded surface area to the original plate surface area) has significant and direct impact on degradation of ultimate capacity of plates among other factors, i.e., size, depth of pits, slenderness of plate, etc. Thicker plate (β=1.34) possibly has higher capacity than thinner plate (β=2.34 or 3) even if DOP of the former is considerably larger than the later,say, as much as 15.45%. However, thickness effect seems neglectable with increasing slenderness to 3 or so. With this regard, DOP is effective and sufficient to denote the effect of pits on ultimate compressive strength of mild steel thin plates.