| Author Name | Affiliation | | Shanhua Xu | School of Civil Engineering, Xi’an University of Architecture and Technology, Xi’an 710055, China | | Songbo Ren | School of Civil Engineering, Xi’an University of Architecture and Technology, Xi’an 710055, China
School of Civil Engineering and Architecture, Southwest University of Science and Technology, Mianyang 621010, Sichuan, China | | Youde Wang | School of Civil Engineering, Xi’an University of Architecture and Technology, Xi’an 710055, China |
|
| Abstract: |
| In order to analyze the distribution and characterizations of corrosion pits on the corroded surface, the steel surface data was measured. Based on the method of the interacting pits, the types of pits corresponding to different exposure time were observed and categorized for completely understanding the effects on the fatigue behavior. The results showed that the conditions for estimating whether the pits interfere with each other should not be ignored; exposure time with 2 years was a critical time. The exposure time and the interacting pits can observably reduce the fatigue life of corroded steel. From these conclusions, the method of fatigue crack growth rate with the multi-pits interaction (FCGR-MPI) was developed and used to predict the fatigue behavior of corroded steel affected with the interacting pits. The predicted lives were also well agreed with the experimental results. |
| Key words: pit characterization exposure time pits interaction fatigue crack growth rate predicted life |
| DOI：10.11916/j.issn.1005-9113.15200 |
| Clc Number:TU501; TG171 |
| Fund: |
|
| Descriptions in Chinese: |
| 点蚀坑对Q235钢材疲劳性能影响 研究 徐善华1，任松波1，2，王友德1 (1.西安建筑科技大学 土木工程学院，西安 710055； 2.西南科技大学 土木工程与建筑学院，绵阳 621010，四川) 创新点说明：本文首先将锈蚀钢材表面点蚀损伤按照损伤特征进行分类，然后，将点蚀坑间交互作用引入交变荷载作用下锈蚀钢材裂纹扩展的研究问题中，增加了锈蚀钢材预测疲劳寿命的准确性。 研究目的： 研究点蚀坑交互作用对锈蚀钢材疲劳裂纹扩展过程的影响。 研究方法： (1) 钢材试件锈蚀过程采用自然环境腐蚀方式，锈蚀龄期分别设置为0.5年、1年、2年以及4年。 (2) 利用PS50三维非接触形貌采集仪对锈蚀钢材表面形貌数据进行扫描采集，并凭借MATLAB软件平台对腐蚀表面点蚀损伤特征参数进行统计分析。 (3) 利用塑性力学理论，建立了相邻点蚀坑交互作用启动临界条件模型。 结果： (1) 基于相邻点蚀坑的交互作用，量化了不同状态点蚀坑群下的交互因子。 (2) 通过相邻点蚀坑交互因子作用，建立了基于交互作用下锈蚀钢材疲劳裂纹扩展速率计算模型，该模型的计算结果更符合真实实验。 结论： (1) 钢材在大气环境下，腐蚀初期，点蚀损伤主要以独立点蚀坑状态存在；随着腐蚀时间持续，点蚀坑逐渐连接，交互，甚至重叠。 (2) 随着腐蚀时间持续，钢材试件裂纹扩展曲线的起裂越早。当腐蚀时间超过2年，锈蚀钢材裂纹扩展速率可利用基于交互作用下锈蚀钢材疲劳裂纹扩展速率计算模型进行预测。 关键词：点蚀特征;腐蚀时间;点蚀坑交互;疲劳裂纹扩展速率;预测寿命 |
