黄云, 张清华, 郭亚文, 卜一之. 钢桥面板纵肋与横隔板焊接细节表面缺陷及疲劳效应研究[J]. 工程力学, 2019, 36(3): 203-213,223. DOI: 10.6052/j.issn.1000-4750.2017.12.0973
引用本文: 黄云, 张清华, 郭亚文, 卜一之. 钢桥面板纵肋与横隔板焊接细节表面缺陷及疲劳效应研究[J]. 工程力学, 2019, 36(3): 203-213,223. DOI: 10.6052/j.issn.1000-4750.2017.12.0973
HUANG Yun, ZHANG Qing-hua, GUO Ya-wen, BU Yi-zhi. RESEARCH ON SURFACE DEFECTS AND FATIGUE EFFECTS AT RIB-TO-CROSSBEAM WELDED JOINTS OF ORTHOTROPIC STEEL BRIDGE DECKS[J]. Engineering Mechanics, 2019, 36(3): 203-213,223. DOI: 10.6052/j.issn.1000-4750.2017.12.0973
Citation: HUANG Yun, ZHANG Qing-hua, GUO Ya-wen, BU Yi-zhi. RESEARCH ON SURFACE DEFECTS AND FATIGUE EFFECTS AT RIB-TO-CROSSBEAM WELDED JOINTS OF ORTHOTROPIC STEEL BRIDGE DECKS[J]. Engineering Mechanics, 2019, 36(3): 203-213,223. DOI: 10.6052/j.issn.1000-4750.2017.12.0973

钢桥面板纵肋与横隔板焊接细节表面缺陷及疲劳效应研究

RESEARCH ON SURFACE DEFECTS AND FATIGUE EFFECTS AT RIB-TO-CROSSBEAM WELDED JOINTS OF ORTHOTROPIC STEEL BRIDGE DECKS

  • 摘要: 初始焊接缺陷是影响结构件疲劳性能的关键因素之一。在断裂力学评估框架下引入特征化初始焊接缺陷,结合相互作用积分法与复合断裂准则解决由表面缺陷所导致的复合型疲劳裂纹扩展问题,在此基础上编写裂纹扩展模拟程序,建立表面焊接缺陷效应评价方法,通过分析揭示了不同形态和尺度的初始焊接缺陷对于钢桥面板纵肋与横隔板构造细节裂纹扩展关键性度量指标和疲劳寿命预测的影响。结果表明:所建立的方法可有效用于评估焊趾部位表面焊接缺陷对于疲劳性能的效应;面状缺陷对于裂纹扩展度量指标和疲劳寿命预测结果的影响更为显著,其初始缺陷深度和形态均是影响疲劳性能的关键因素,体积型缺陷对于疲劳寿命的影响主要由深度方向的缺陷尺寸决定;焊接缺陷的形态和几何参数取值应根据工程实际和规范建议值共同确定,直接简化为面状缺陷会低估结构件的疲劳寿命;考虑焊接缺陷不确定性的可靠度评估方法尚需进一步研究。

     

    Abstract: The initial weld defect is one of the key factors which have major influences on the fatigue performance of structures and components. Characteristic initial weld defects were introduced into the fracture mechanics evaluation framework, the interaction energy integral method and mixed-mode fracture criterion were adopted to address the fatigue crack propagation caused by surface defects. On this basis, an analytical approach, which can assess the impact of surface defects on fatigue, was established by means of writing a program of simulating fatigue crack growth. Detailed analysis was carried out to reveal the effects of initial weld defects with different shapes and dimensions on the key indices of crack propagation and fatigue life prediction at the rib-to-crossbeam welded joints of orthotropic steel bridge decks. The results indicate that the proposed approach can be effectively applied to evaluate the influences of surface weld defects on the fatigue properties of weld toes. Planar defects have more remarkable influences on the evaluation indices of crack propagation and of predicted fatigue life; initial depth and shape are both critical factors that have a significant impact on fatigue performance;and the influences of volumetric weld defects are mainly controlled by the size in the depth direction. The shape and geometric parameter values of initial weld defects should be determined according to engineering practice and recommended values from specifications, and the fatigue life could be underestimated if all the defects are roughly simplified as planar defects. Further research should be dedicated to the reliability assessment method considering the uncertainty of weld defects.

     

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