朱美春,程 亮,李国强,等.正面角焊缝连接高温后的强度试验[J].深圳大学学报理工版,2016,33(06):620-626.[doi:10.3724/SP.J.1249.2016.06620 ]
Zhu Meichun,Cheng Liang,Li Guoqiang,et al.Experiment on strength of transverse fillet weld connections after high temperature treatment[J].Journal of Shenzhen University Science and Engineering,2016,33(06):620-626.[doi:10.3724/SP.J.1249.2016.06620 ]
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正面角焊缝连接高温后的强度试验
朱美春1,程 亮2,李国强3,王 英1

1)上海师范大学建筑工程学院,上海 201418; 2)中国电力工程顾问集团中南电力设计院有限公司,湖北武汉 430071; 3)同济大学土木工程防灾国家重点实验室,上海200092

结构工程; 钢结构; 焊缝连接; 正面角焊缝; 强度实验; 高温过火; 安全性鉴定; 冷却方式

Experiment on strength of transverse fillet weld connections after high temperature treatment
Zhu Meichun1, Cheng Liang2, Li Guoqiang3, and Wang Ying1

Zhu Meichun1, Cheng Liang2, Li Guoqiang3, and Wang Ying11)College of Civil Engineering, Shanghai Normal University, Shanghai 201418, P.R.China 2)Central Southern China Electric Power Design Institute, China Power Engineering Consulting Group, Wuhan 430071, Hubei Province, P.R.China3)State Key Laboratory for Disaster Reduction in Civil Engineering, Tongji University, Shanghai 200092, P.R.China

structure engineering; steel structure; welded connection; transverse fillet weld; strength experiment; high temperature annealing; safety identification; cooling method

DOI: 10.3724/SP.J.1249.2016.06620

备注

为研究高温过火对正面角焊缝残余强度的影响规律,对43个Q345B钢材双盖板正面角焊缝连接试件进行高温冷却后的拉伸试验. 试件统一设计为正面角焊缝发生断裂,试验参数为过火温度和冷却方式,其中过火温度介于200～900 ℃,冷却方式包括自然冷却和泼水冷却. 结果表明,高温自然冷却后正面角焊缝破坏面角度平均值为19°, 泼水冷却后为16°, 与理论值45°相差较大; 正面角焊缝残余强度随过火温度的升高而下降,泼水冷却情况下强度降低更显著, 最大降低幅度达到37%; 采用三直线模型计算高温后残余强度降低系数,计算结果与试验值吻合良好. 可供火灾后钢结构安全性鉴定参考.

We investigate the effect of heating and cooling on strength of transverse fillet weld connections by tensile test. Fourty-three connection specimens made up of four Q345B steel plates and with four transverse fillet welds were heated to a specified target temperature, then cooled to the ambient temperature, and finally loaded to failure. Experimental parameters are the heating temperature and the cooling method. Seven temperature levels from 200 ℃ to 900 ℃ and two cooling methods including natural cooling and water cooling were chosen. Experimental results show that the average value of fracture angles is 19° for natural cooling specimens, and the value is 16° for water cooling specimens, both quite different from the theoretical value 45°. The post-fire residual strength reduces with the increase of the heating temperature, and generally water cooling leads to higher degradation in strength than natural cooling, whose maximum reduction rate reaches 37%. Tri-linear model is proposed to calculate the variation factor of the post-fire residual strength. The calculated value matches well with the experimental result, which can provide reference for safety identification of steel structures after fire.

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