考虑匹配比和软化效应的高强钢对接焊缝的设计建议  

Design proposal of butt welded joints of high strength steel considering mismatch ratio and softened zone

作　　者：冉明明 李国强[3] 孙飞飞[3] 王彦博 RAN Mingming;LI Guoqiang;SUN Feifei;WANG Yanbo(Ministry of Education Key Laboratory of Deep Underground Science and Engineering,College of Architecture and Environment,Sichuan University,Chengdu 610065,China;Failure Mechanics&Engineering Disaster Prevention and Mitigation,Key Laboratory of Sichuan Province,Sichuan University,Chengdu 610065,China;State Key Laboratory for Disaster Reduction in Civil Engineering,Tongji University,Shanghai 200092,China)

机构地区：[1]四川大学建筑与环境学院深地科学与工程教育部重点实验室,四川成都610065 [2]四川大学破坏力学与工程防灾减灾四川省重点实验室,四川成都610065 [3]同济大学土木工程防灾国家实验室,上海200092

出　　处：《建筑结构学报》2022年第11期275-286,共12页Journal of Building Structures

基　　金：中国博士后科学基金项目(2020M673224);中央高校基本科研业务费专项(20826041D4131)。

摘　　要：针对高强度结构钢在焊接热循环作用下热影响区域可能产生软化现象,且高强钢焊接时将遇到焊材强度匹配的问题,基于高强钢对接焊缝的试验研究、数值分析和理论研究的结果,对考虑焊接软化和焊材强度匹配的强度模型进行简化,进而提出便于设计的简化公式。通过对试验数据、欧洲规范EC3预测值、强度模型预测值和简化公式预测值的对比,得出强度模型和简化公式对接头强度的预测值较为准确,而欧洲规范EC3高估了对接接头强度。为了进一步地将简化公式应用于工程设计,通过搜集和汇总焊缝加工尺寸、高强钢力学性能以及试件实际的工作性能等三方面的数据,对简化公式进行可靠度分析,当安全系数为4.5时,抗力分项系数取为0.84。对我国规范中高强钢对接焊缝连接的设计方法提出设计建议,即在对接焊缝受拉承载力计算式中考虑接头的综合强度,该综合强度取决于钢材强度、焊材强度、软化区情况和约束情况。As microstructure of the high strength steel is very sensitive to the heat input energy,significant reductions in both the yield and tensile strength of the heat affected zone(HAZ)of the welded sections will occur.In addition,unmatched welded joints is permitted in welding high strength steel.In this paper,a summary work of experimental,numerical and theoretical study on butt welded joints of high strength steel was conducted at first,and then the strength model proposed by the authors,which considered the effects of under-matched and the softened HAZ zone,was simplified for utilizing in design.A simplified formula for butt welded joints was proposed.The comparison between the test data,predicted results by Eurocode 3(EC3)and predicted results by the strength model and simplified formula indicates that the predictions of the proposed strength model are in reasonable agreement with the test data,whereas EC3 overestimates the strength of butt joints in situations with a wide softened HAZ zone.In order to propose a design formula based on the simplified formula,the reliability analysis was conducted by analyzing the geometry,material mechanical properties and working performance in order to obtain the resistance factor.When the safety coefficient is 4.5,the resistance factor is 0.84.Finally,a design proposal of butt welded joints made of high strength steels was proposed.The design method was taking comprehensive strength into account,which depends on the ultimate strengths of base metal and filler metal,soften zone and constraint.

关 键 词：高强钢 焊缝连接 软化现象 欠强匹配 可靠度分析 设计建议 

分 类 号：TU511.3[建筑科学—建筑技术科学] TU02.6