基于宽板拉伸试验的Q690qE高性能桥梁钢断裂韧性研究  

Research on Fracture Toughness of Q690qE High Performance Bridge Steel Based on Wide Plate Tensile Test

作　　者：左照坤 鞠晓臣 赵欣欣 刘晓光 ZUO Zhao-kun;JU Xiao-chen;ZHAO Xin-xin;LIU Xiao-guang(China Academy of Railway Sciences,Beijing 100081,China;Railway Engineering Research Institute,China Academy of Railway Sciences Co. ,Ltd. ,Beijing 100081,China)

机构地区：[1]中国铁道科学研究院,北京100081 [2]中国铁道科学研究院集团有限公司铁道建筑研究所,北京100081

出　　处：《桥梁建设》2022年第1期56-63,共8页Bridge Construction

基　　金：国家重点研发计划项目(2017YFB0304805);国家自然科学基金高铁联合基金资助项目(U1934209);中国铁道科学研究院集团有限公司国家创新平台开放基金项目(2021YJ167)。

摘　　要：为研究应用于桥梁钢结构的Q690qE钢防脆断性能,以主跨408 m的汉江湾桥为背景,设计、制作Q690qE钢32 mm板厚母材、32 mm板厚焊缝、50 mm板厚母材、50 mm板厚焊缝4组试件,进行不同温度下的宽板拉伸试验,分析其断裂韧性。将宽板拉伸试验值作为断裂抗力,采用有限元法计算汉江湾桥典型受拉杆件在较不利工作应力下的断裂驱动力,评价桥梁钢结构采用Q690qE钢时的低温防脆断性能。结果表明:Q690qE钢32 mm板厚母材具有良好的低温防脆断性能,50 mm板厚母材的断裂韧性随温度降低具有明显下降趋势;在温度低于-20℃时,Q690qE钢32 mm、50 mm板厚焊缝的断裂韧性随温度降低具有下降趋势;与Q500qE钢相比,Q690qE钢母材和焊缝均具有较好的断裂韧性;汉江湾桥典型受拉杆件采用Q690qE钢时能够满足低温防脆断的要求。The Hanjiangwan Bridge that has a main span of 408 m is applied as a case to study the brittle fracture resistance of specialist Q690qE steel for bridge structures.Four specimens,including the 32 mm-thick base metal,32 mm-thick plate with weld joint,50 mm-thick base metal and 50 mm-thick plate with weld joint,were designed and fabricated for the wide plate tenssile tests under different temperatures,and based on which,the fracture toughness of the Q690qE steel was analyzed.Then,with the results of the wide plate tensile tests as the fracture resistances,the fracture driving forces of the typical tensile members of the Hanjiangwan Bridge under adverse working stresses were calculated by finite element method,and the low-temperature brittle fracture resistance of the Q690qE steel bridge structure was evaluated.It is shown that the 32 mm-thick base metal exhibits good low-temperature brittle fracture resistance,while the fracture toughness of 50 mm-thick base metal displays evident reduction tendency as the temperature drops.When the temperature is below-20℃,the fracture toughness of both the 32 mm-and 50 mm-thick base metals of Q690qE steel tends to decrease as temperature drops.Compared with the Q500qE steel,the base metal and weld joint of Q690qE own better fracture toughness.In the Hanjiangwan Bridge,the typical tensile members are made from Q690qE steel to meet the low-temperature brittle fracture protection requirements.

关 键 词：桥梁钢结构 Q690qE桥梁钢 板厚 温度 断裂韧性 宽板拉伸试验 有限元法 

分 类 号：U444[建筑科学—桥梁与隧道工程] U441.6[交通运输工程—道路与铁道工程]