交变应力与环境耦合作用下拉索腐蚀疲劳损伤机理研究

发布时间：2018-01-13 20:17

本文关键词：交变应力与环境耦合作用下拉索腐蚀疲劳损伤机理研究　出处：《公路》2015年04期 　论文类型：期刊论文

【摘要】：通过开展室内盐雾加速腐蚀试验,研究分析了各种应力状态下腐蚀钢丝的腐蚀失重量及弹性模量、抗拉强度等力学性能的变化,得出腐蚀钢丝各种力学性能中断后伸长率对疲劳腐蚀最为敏感的结论。在试验开展的基础上,以细观损伤力学为研究手段,并结合断裂力学强度准则,分析了环境腐蚀、应力腐蚀和疲劳腐蚀各自的特征、机理。腐蚀斜拉索的腐蚀疲劳损伤主要是由于腐蚀造成的钢丝表面的蚀坑,进而导致应力集中现象,加之氢致开裂,导致裂纹不断萌生、发展,研究分析了应用腐蚀疲劳裂纹扩展门槛值作为点蚀坑向腐蚀疲劳裂纹转化的判据的方法,并通过数值手段,分析了钢丝全面腐蚀、表面蚀坑深度、蚀坑形状和蚀坑纵向净间距对钢丝应力分布状态和疲劳寿命的影响。
[Abstract]:Through indoor salt spray accelerated corrosion test, the changes of corrosion weight loss, elastic modulus, tensile strength and other mechanical properties of corroded steel wire under various stress conditions were studied and analyzed. It is concluded that the elongation of corroded steel wire is most sensitive to fatigue corrosion after various mechanical properties are interrupted. On the basis of the test, the meso-damage mechanics is taken as the research means and the strength criterion of fracture mechanics is combined. The characteristics and mechanism of environmental corrosion, stress corrosion and fatigue corrosion are analyzed. The corrosion fatigue damage of cable corrosion is mainly caused by corrosion of steel wire surface corrosion pit, which leads to stress concentration phenomenon. In addition, the hydrogen induced cracking leads to the crack initiation and development. The method of applying the corrosion fatigue crack growth threshold as the criterion of the transformation of the pitting pit to the corrosion fatigue crack is studied and analyzed, and the numerical method is adopted. The effects of overall corrosion of steel wire, depth of surface pit, shape of pit and net distance between pits on stress distribution and fatigue life of steel wire are analyzed.
【作者单位】：重庆交通大学土木建筑学院;
【分类号】：U441.4
【正文快照】： 斜拉桥缆索系统采取的防腐措施主要有钢丝镀锌法、钢绞线环氧涂抹法、防锈脂填充法、高密度聚乙烯包裹法等,极大地增加了缆索系统的耐蚀性和使用寿命。但是,采用封闭索体、灌浆防腐的效果并不十分显著。由于拉索实际所处环境的复杂性及制作和施工过程中的人为因素,PE护套在使

【参考文献】