Q460高强钢材及T形对接接头超低周疲劳特性  

Ultra-low cycle fatigue properties of Q460 high strength T-shape butt weld joints

作　　者：邱晨 邢佶慧[1] 张丽 王涛[1] QIU Chen;XING Jihui;ZHANG Li;WANG Tao(School of Civil Engineering,Beijing Jiaotong University,Beijing 100044,China;China Railway Huatie Engineering Design GROP Co.,Ltd.,Beijing 100071,China)

机构地区：[1]北京交通大学土木建筑工程学院,北京100044 [2]中铁华铁工程设计集团有限公司,北京100071

出　　处：《振动与冲击》2021年第16期166-174,共9页Journal of Vibration and Shock

基　　金：国家自然科学基金面上项目(51578045,51878029)。

摘　　要：为明确高强钢材焊接接头的超低周疲劳特性,进行了Q460高强钢母材、焊缝、热影响区钢材及T形全熔透对接焊接接头的超低周疲劳加载试验,基于试验结果校正了Q460高强钢材的随动-等向混合强化材性参数,识别了其循环微孔扩张模型(CVGM)微观断裂预测模型参数,在ABAQUS软件中建立Q460高强钢T形焊接接头的精细化三维有限元模型,采用CVGM模型准确预测了焊接接头循环荷载下的延性断裂行为,继而变化板厚、板件夹角和板件标准段长度针对接头断裂性能进行了参数分析。结果表明,往复荷载作用下,Q460高强T形对接接头失效前内部存在两处危险地带,即钢板内逐步形成的塑性条带和热影响区,接头的断裂特性取决于这两处的缺陷和损伤累积状况。随着板厚、板件夹角和板件标准段长度的增加,对接接头的超低周疲劳寿命断裂延长,位移延性系数增大。In order to study the ultra-low fatigue properties of high strength steel welded joints,tests on weld metal,heat-affected zone and base metal of Q460 high strength steel materials as well as T-shape fully penetration butt weld connections were performed under ultra-low cyclic loads.Based on tested results of Q460 steel coupons,both combined kinematic-isotropic hardening material parameters and cyclic void growth model(CVGM)micro-mechanical fracture model parameters were calibrated.Three-dimensional refined FE analysis models were built and incorporated with the CVGM method in ABAQUS to predict ductile fracture behaviors of Q460 high strength T-shape butt weld joints under cyclic loads.Furthermore,parametric analyses were also conducted on T-shape butt weld joints with varying plate thickness,plate angles,and standard segment length of plates.Research results show that there are two dangerous areas in the T-shape joint,ie.plastic strip developed in the middle part of the steel plate and heat-affected zone.Fracture properties of the joint are determined according to defects and damage accumulation status in these two areas.Ultra-low cycle fatigue life and ductility of T-shape joint increase with plate thickness,plate angles and standard segment length of plates.

关 键 词：Q460高强钢 T形 全熔透对接接头 超低周疲劳 断裂 延性 

分 类 号：TU392.4[建筑科学—结构工程]