摘要
为研究点蚀损伤钢板延性退化机理,采用三维形貌测量技术测得不同锈蚀程度钢板表面点蚀坑几何参数,并通过单调拉伸试验和有限元数值分析研究了点蚀损伤对钢板延性的影响.此外,根据应力三轴度与点蚀坑深度、间距及深径比间的关系,提出了与点蚀坑几何尺寸相关的点蚀损伤钢板等效延性断裂准则.结果表明:表面点蚀坑深度及深径比均随钢板锈蚀程度的增加而线性增长;点蚀坑几何尺寸的增长显著改变了钢板内部应力三轴度的大小和分布,降低了等效塑性断裂应变,加快了颈缩阶段钢板内部裂纹的萌生和扩展,从而导致锈蚀钢板极限伸长率逐渐退化;采用等效延性断裂准则能准确地模拟点蚀损伤导致的钢板延性退化现象.
To investigate the mechanism of ductility degradation of the steel plates with pitting dam-age, the pitting geometric parameters on the surface of the steel plates with different corrosion degrees were tested by three-dimensional （3D） profile measurement technology, and the effects of pitting damage on the ductility of steel plates were studied by the monotonic tensile tests and finite element numerical analysis. In addition, the equivalent ductile fracture criterion of the steel plates with pitting damage related to the pitting geometric parameters was proposed based on the relationships between the stress triaxiality and the pitting depth, the pitting distance, and the depth-radius ratio. The results show that both the pitting depth and the pitting depth-radius ratio increase linearly with the increase of the corrosion degree. The increase of the geometric dimension of the pits changes the magnitude and the distribution of the triaxial stress of the steel plates significantly, reduces the critical equivalent plastic strain, and accelerates the initiation and propagation of the cracks at the necking stage, inducing the gradual degradation of the ultimate elongation of the corroded steel plates. The ductility degradation of steel plates caused by pitting damage can be accurately simulated by the equivalent ductile fracture criterion.
出处
《东南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2016年第6期1257-1263,共7页
Journal of Southeast University：Natural Science Edition
基金
国家自然科学基金资助项目(51378417)
国家重点研发计划资助项目(2016YFC0701305)
关键词
点蚀损伤钢板
延性退化
点蚀坑几何参数
应力三轴度
等效延性断裂准则
steel plates with pitting damage
ductility degradation
pitting geometric parameters
stress triaxiality
equivalent ductile fracture criterion
