钢箱梁顶板-U肋疲劳裂纹钢板加固参数与效果分析
Parameters and Effect Analysis of Steel Plate Reinforcement for Fatigue Crack of U Rib-to-deck Welded Joint in Steel Box Girder
肖龙 1吉伯海 2沈翔 1陈欣 3高天2
作者信息
- 1. 宁波市杭州湾大桥发展有限公司,浙江 宁波 315000
- 2. 河海大学 土木与交通学院,江苏 南京 210098
- 3. 江苏宁靖盐高速公路有限公司,江苏 泰州 225300
- 折叠
摘要
为研究钢板加固钢箱梁顶板-U肋疲劳裂纹的具体加固参数与加固效果,以加固件长度与厚度、是否设置加劲肋为变化参数,建立局部有限元分析模型,通过分析顶板-U肋焊趾处应力,评估受损构件的钢板加固效果,并提取裂纹尖端应力强度因子,研究不同参数对于加固效果的影响规律.结果表明:采用钢板加固顶板-U肋焊缝细节,可使模型中焊趾应力峰值降低约 40%;胶层破坏时通常从顶板处开始破坏,现场加固时应确保顶板处胶层粘贴紧固;当钢板长度大于裂纹长度时,钢板长度对裂纹尖端应力水平影响较小,加固时保证钢板能够完全覆盖裂纹即可;当钢板板厚达母材板厚的1/2 时加固效果趋于稳定,实桥加固时可取板厚为母材板厚的一半;与未加固裂纹相比,采用带加劲肋钢板可将裂纹尖端应力强度因子降低约50%,建议在加固时采用带加劲肋钢板,进一步提升加固效果.
Abstract
To analyze the specific reinforcement parameters and the reinforcing effect of steel plate reinforcement for fa-tigue cracks in the U rib-to-deck in steel box girder,local finite element analysis models were established.The model included reinforcement parameters of length,thickness,and the presence of stiffening ribs.The analysis of stress in the weld toe of the U rib-to-deck evaluated the efficiency of steel plate reinforcement in damaged members,and investi-gating the influence law of various factors on the reinforcement effect by extracting the stress intensity factor at the crack tip.The results demonstrated that utilizing steel plates to reinforce the U rib-to-deck weld detail reduces the peak weld toe stress in the model by approximately 40%.When the adhesive layer breaks down,it typically begins at the top plate.Therefore,it is necessary for site reinforcement to tightly adhere the adhesive layer at the top plate.When the length of the steel plate exceeds that of the crack,the impact of the former on the stress level at the crack's tip de-clines.Therefore,it suffices to ensure complete coverage of the crack by the steel plate during reinforcement.When the thickness of a steel plate is up to 1/2 that of the parent material plate,the reinforcement effect tends to stabilize.In such cases,it is recommended that the reinforcement plate thickness of half the thickness of the parent material plate.Using steel plates with stiffening ribs reduces the stress intensity factor at the crack tip by approximately 50%compared to unreinforced cracks.It is recommended to utilize steel plates with stiffening ribs in the reinforcement to enhance the reinforcement effect.
关键词
钢箱梁/顶板-U肋/焊缝/疲劳裂纹/钢板加固/有限元分析Key words
steel box girder/U rib-to-deck/welding seam/fatigue crack/steel plate reinforcement/finite ele-ment analysis引用本文复制引用
出版年
2024
NETL
NSTL
维普
万方数据