中文核心期刊
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重庆交通大学学报（自然科学版）

重庆交通大学学报（自然科学版） ›› 2017, Vol. 36 ›› Issue (9): 1-5.DOI: 10.3969/j.issn.1674-0696.2017.09.01

• 桥梁与隧道工程 •    下一篇

钢箱梁角焊缝表面裂纹应力特征及影响因素分析

吉伯海，谢曙辉，傅中秋，姚悦   

  1. （河海大学 土木与交通学院，江苏 南京 210098）
  • 收稿日期:2016-03-30 修回日期:2016-05-21 出版日期:2017-09-20 发布日期:2017-09-20
  • 作者简介:吉伯海(1966—)，男，江苏扬州人，教授，博士，博士生导师，主要从事钢桥疲劳与维护方面的研究。E-mail：hhbhji@163.com。
  • 基金资助:
    国家自然科学基金面上项目(51478163)；江苏省交通运输科技与成果转化项目(2017Y09)

Stress Characteristics and Influence Factors of Surface Crack near Fillet Weld in Steel Box Girder

JI Bohai, XIE Shuhui, FU Zhongqiu, YAO Yue   

  1. (School of Civil and Transportation Engineering, Hohai University, Nanjing 210098, Jiangsu, P.R.China)
  • Received:2016-03-30 Revised:2016-05-21 Online:2017-09-20 Published:2017-09-20

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摘要： 结合钢箱梁局部模型试件，针对角焊缝表面裂纹进行数值模拟，进行了裂纹尖端与裂纹前缘应力分布分析，并基于最大切向应力准则计算了裂纹面参考点的应力强度因子，最后结合疲劳裂纹实际扩展变化，考虑了不同裂纹形状对应力和应力强度因子的影响。分析结果表明：裂纹尖端存在严重的应力集中，裂纹区应力下降明显，裂纹前缘的应力水平与未出现裂纹时相同位置截面上表面应力水平相当；裂纹面受拉压应力，II型和III型应力强度因子基本为0，I型应力强度因子总体上随着参考点角度的增大而逐渐减小；裂纹尖端应力与裂纹短长轴比基本呈线性增大关系，在短长轴比0.6以后增速减缓，随着短长轴比的增大，裂纹深度方向前缘处应力强度因子变化幅度较裂纹尖端处更大，与长裂纹区相比，短裂纹区这种差异性较明显。

关键词: 桥梁工程, 疲劳, 表面裂纹, 应力, 应力强度因子

Abstract: Based on specimen of steel girder bridge local model, the numerical simulation of fillet weld surface crack was carried out. Stress distribution of crack tip and front was analyzed, and stress intensity factor of reference point was calculated based on maximum tangential stress criterion. Additionally, according to actual fatigue crack shape change during propagation, the influence of different crack shapes on stress and stress intensity factor was considered. Analysis results indicate that crack tip appears severe stress concentration phenomena and stress of crack zone decreases obviously. Stress level of crack front is closed to that of cross-section at the same location surface without crack. Under tensile stress, stress intensity factor of type II and type III is approximately equal to zero; and KI decreases gradually with the increase of angles of surface reference points on the whole. Crack tip stress increases linearly with the ratio of minor axis to major axis, and the growth rate slows down when the ratio is larger than 0.6. With the increase of the ratio of minor axis to major axis, the change range of stress intensity factor at front along crack depth is larger than that at crack tip, and comparing with long crack zone, this difference is more obvious in short crack zone.

Key words: bridge engineering, fatigue, surface crack, stress, stress intensity factor (SIF)

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