| 钢箱梁疲劳裂纹气动冲击法维修效果评估 |
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| 引用本文： | 刘嘉正,吉伯海,袁周致远,刘青茹.钢箱梁疲劳裂纹气动冲击法维修效果评估[J].福州大学学报(自然科学版),2020,48(4):511-516. |
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| 作者姓名： | 刘嘉正 吉伯海 袁周致远 刘青茹 |
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| 作者单位： | 河海大学 土木与交通学院,河海大学 土木与交通学院,河海大学 土木与交通学院,河海大学 土木与交通学院 |
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| 基金项目： | 国家重点研发计划资助项目 |
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| 摘 要： | 以实桥疲劳裂纹为研究对象,从应力和应力强度因子角度评估气动冲击维修方法的现场实施效果.对维修前后疲劳裂纹尖端附近的应力分别进行24 h数据采集,并采用雨流计数法,探讨裂纹尖端应力幅的变化规律.结合应力强度因子测试理论,对比研究裂纹尖端应力强度因子幅的变化规律.研究结果表明:本测点疲劳裂纹为典型的Ⅰ-Ⅱ复合型裂纹,维修后疲劳裂纹尖端张拉和剪切应力幅均得到有效降低,改善了裂纹尖端受力条件.高应力强度因子幅的循环次数显著降低,表明气动冲击维修技术对于制约复合型裂纹扩展具有良好效果.
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| 关 键 词： | 疲劳裂纹 气动冲击维修 应力幅 应力强度因子 |
| 收稿时间： | 2019/10/31 0:00:00 |
| 修稿时间： | 2019/12/6 0:00:00 |
Evaluation of fatigue crack repairing effect by pneumatic impact method in steel box girder |
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| LIU Jiazheng,JI Bohai,YUAN Zhouzhiyuan and LIU Qingru.Evaluation of fatigue crack repairing effect by pneumatic impact method in steel box girder[J].Journal of Fuzhou University(Natural Science Edition),2020,48(4):511-516. |
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| Authors: | LIU Jiazheng JI Bohai YUAN Zhouzhiyuan and LIU Qingru |
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| Institution: | College of Civil and Transportation Engineering,Hohai University,College of Civil and Transportation Engineering,Hohai University,College of Civil and Transportation Engineering,Hohai University,College of Civil and Transportation Engineering,Hohai University |
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| Abstract: | The retrofitted effect of pneumatic impact method was evaluated by both stress and stress intensity factor (SIF) based on the fatigue cracks in real-world bridge. The daily (24h) stress near the fatigue crack tip before and after pneumatic impact repairing was collected, and the stress amplitude distribution was determined through the rain-flow counting method. The variation of SIF amplitude at the crack tip, was compared and investigated according to the SIF testing theory. The results shows that the fatigue crack at the test point is a typical I-II mixed mode crack. Both the values of tensile stress amplitude and shear stress amplitude at the fatigue crack tip decrease after repairing, indicating that the stress condition at the crack tip is improved. The numbers of high SIF amplitude are reduced, indicating that the pneumatic impact method has a good effect on restraining the propagation of mixed mode crack. |
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| Keywords: | fatigue crack pneumatic impact repairing stress amplitude stress intensity factor |
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