X形圆钢管相贯节点焊缝断裂预测及承载力分析
摘要：为了验证应力加权损伤模型(SWDM)对相贯节点在单调荷载作用下延性断裂预测的适用性，对正交设计的23个X形圆钢管相贯节点进行有限元分析。应用空穴扩张模型(VGM)和SWDM,得到了荷载和断裂点损伤度曲线，通过洛德角参数的变化，分析了断裂点的应力状态，对比了VGM和SWDM预测结果；运用ABAQUS子程序模拟了焊缝破坏过程，分析了节点几何参数对焊缝承载力的影响。结果表明：SWDM预测的断裂荷载要低于VGM,断裂点的应力状态是由轴对称拉伸或压缩状态向平面应变状态的趋势变化，通过引入洛德角参数，SWDM能准确地模拟节点在不同应力状态下的损伤累积，预测精度高于VGM,适用性更好；焊缝的开裂始于鞍点处，并迅速向冠点发展，导致节点破坏；节点支主管壁厚一定时，支主管外径比和主管径厚比越大，焊缝承载力越低；《钢结构设计标准》(GB 50017—2017)中焊缝承载力计算公式未考虑焊缝受力不均匀的影响，计算结果会出现偏不安全的情况。
关键词：相贯节点；应力加权损伤模型；空穴扩张模型；断裂预测模型；焊缝承载力
尊敬的用户，本篇文章需要2元，点击支付交费后阅读
限时优惠福利：领取VIP会员
全年期刊、VIP视频免费!
全年期刊、VIP视频免费!
参考文献[1] 黄政华，周丽霞，梁健.相贯节点桁架网格结构的受力特性与有限元分析模型[J].贵州大学学报(自然科学版),2017,34(1):72-76.
[2] 陈以一，陈扬骥.钢管结构相贯节点的研究现状[J].建筑结构，2002,32(7):52-55,31.
[3] XUE L.A unified expression for low cycle fatigue and extremely low cycle fatigue and its implication for monotonic loading[J].International Journal of Fatigue,2008,30(10/11):1691-1698.
[4] HANCOCK J W,MACKENZIE A C.On the mechanisms of ductile failure in high-strength steels subjected to multi-axial stress-states[J].Journal of the Mechanics and Physics of Solids,1976,24(2/3):147-160.
[5] RICE J R,TRACEY D M.On the ductile enlargement of voids in triaxial stress fields[J].Journal of the Mechanics and Physics of Solids,1969,17(3):201-217.
[6] KANVINDE A M,DEIERLEIN G G.Finite-element simulation of ductile fracture in reduced section pull-plates using micromechanics-based fracture models[J].Journal of Structural Engineering,2007,133(5):656-664.
[7] LIAO F F,WANG W,CHEN Y Y.Parameter calibrations and application of micromechanical fracture models of structural steels[J].Structural Engineering and Mechanics,2012,42(2):153-174.
[8] 王伟，廖芳芳，陈以一.基于微观机制的钢结构节点延性断裂预测与裂后路径分析[J].工程力学，2014,31(3):101-108,115.
[9] 石小龙，黄政华，夏义舒.基于微观机制圆钢管T型相贯节点极限承载力研究[J].四川建筑科学研究，2019,45(6):25-29.
[10] WANG Y Q,ZHOU H,SHI Y J,et al.Fracture prediction of welded steel connections using traditional fracture mechanics and calibrated micromechanics based models[J].International Journal of Steel Structures,2011,11(3):351-366.
[11] 尹越，车鑫宇，韩庆华，等.基于微观断裂机制的XK型相贯节点极限承载力分析[J].土木工程学报，2017,50(7):20-26,121.
[12] KANVINDE A M,DEIERLEIN G G.Cyclic void growth model to assess ductile fracture initiation in structural steels due to ultra low cycle fatigue[J].Journal of Engineering Mechanics,2007,133(6):701-712.
[13] SMITH C M,DEIERLEIN G G,KANVINDE A M.A stress-weighted damage model for ductile fracture initiation in structural steel under cyclic loading and generalized stress states[D].California:Stanford University,2014:161-244.
[14] WEN H J,MAHMOUD H.New model for ductile fracture of metal alloys.I:monotonic loading[J].Journal of Engineering Mechanics,2016,142(2):04015088.
[15] BAO Y B,WIERZBICKI T.On fracture locus in the equivalent strain and stress triaxiality space[J].International Journal of Mechanical Sciences,2004,46(1):81-98.
[16] 陈博林.基于微观损伤模型的Q460C钢材断裂行为研究[D].北京：北京交通大学，2017.
[17] 夏义舒，黄政华，石小龙.基于微观机制圆钢管X型相贯节点焊缝延性断裂预测及Lode角参数分析[J].空间结构，2020,26(4):75-82.
[18] 陈爱国，王开明，邢佶慧，等.单调荷载下Q345钢焊缝金属的延性断裂性能研究[J].工程力学，2020,37(1):88-97.
[19] 钢结构设计标准：GB 50017—2017[S].北京：中国建筑工业出版社，2017.
[20] 马昕煦，王伟，陈以一.正交X形圆钢管相贯节点焊缝断裂的试验与机理分析[J].建筑结构学报，2018,39(3):139-148.
[2] 陈以一，陈扬骥.钢管结构相贯节点的研究现状[J].建筑结构，2002,32(7):52-55,31.
[3] XUE L.A unified expression for low cycle fatigue and extremely low cycle fatigue and its implication for monotonic loading[J].International Journal of Fatigue,2008,30(10/11):1691-1698.
[4] HANCOCK J W,MACKENZIE A C.On the mechanisms of ductile failure in high-strength steels subjected to multi-axial stress-states[J].Journal of the Mechanics and Physics of Solids,1976,24(2/3):147-160.
[5] RICE J R,TRACEY D M.On the ductile enlargement of voids in triaxial stress fields[J].Journal of the Mechanics and Physics of Solids,1969,17(3):201-217.
[6] KANVINDE A M,DEIERLEIN G G.Finite-element simulation of ductile fracture in reduced section pull-plates using micromechanics-based fracture models[J].Journal of Structural Engineering,2007,133(5):656-664.
[7] LIAO F F,WANG W,CHEN Y Y.Parameter calibrations and application of micromechanical fracture models of structural steels[J].Structural Engineering and Mechanics,2012,42(2):153-174.
[8] 王伟，廖芳芳，陈以一.基于微观机制的钢结构节点延性断裂预测与裂后路径分析[J].工程力学，2014,31(3):101-108,115.
[9] 石小龙，黄政华，夏义舒.基于微观机制圆钢管T型相贯节点极限承载力研究[J].四川建筑科学研究，2019,45(6):25-29.
[10] WANG Y Q,ZHOU H,SHI Y J,et al.Fracture prediction of welded steel connections using traditional fracture mechanics and calibrated micromechanics based models[J].International Journal of Steel Structures,2011,11(3):351-366.
[11] 尹越，车鑫宇，韩庆华，等.基于微观断裂机制的XK型相贯节点极限承载力分析[J].土木工程学报，2017,50(7):20-26,121.
[12] KANVINDE A M,DEIERLEIN G G.Cyclic void growth model to assess ductile fracture initiation in structural steels due to ultra low cycle fatigue[J].Journal of Engineering Mechanics,2007,133(6):701-712.
[13] SMITH C M,DEIERLEIN G G,KANVINDE A M.A stress-weighted damage model for ductile fracture initiation in structural steel under cyclic loading and generalized stress states[D].California:Stanford University,2014:161-244.
[14] WEN H J,MAHMOUD H.New model for ductile fracture of metal alloys.I:monotonic loading[J].Journal of Engineering Mechanics,2016,142(2):04015088.
[15] BAO Y B,WIERZBICKI T.On fracture locus in the equivalent strain and stress triaxiality space[J].International Journal of Mechanical Sciences,2004,46(1):81-98.
[16] 陈博林.基于微观损伤模型的Q460C钢材断裂行为研究[D].北京：北京交通大学，2017.
[17] 夏义舒，黄政华，石小龙.基于微观机制圆钢管X型相贯节点焊缝延性断裂预测及Lode角参数分析[J].空间结构，2020,26(4):75-82.
[18] 陈爱国，王开明，邢佶慧，等.单调荷载下Q345钢焊缝金属的延性断裂性能研究[J].工程力学，2020,37(1):88-97.
[19] 钢结构设计标准：GB 50017—2017[S].北京：中国建筑工业出版社，2017.
[20] 马昕煦，王伟，陈以一.正交X形圆钢管相贯节点焊缝断裂的试验与机理分析[J].建筑结构学报，2018,39(3):139-148.
Fracture prediction and bearing capacity analysis of weld of tubular circular hollow section X-joints
Abstract: In order to verify the applicability of stress-weighted damage model(SWDM)to the prediction of ductile fracture of tubular joints under monotonic loading, the finite element analysis was carried out on 23 tubular circular hollow section X-joints with orthogonal design. Using void growth model(VGM)and SWDM, the load and fracture point damage curves were obtained, the stress state of the fracture point was analyzed through the change of Lode angle parameters. The prediction results of VGM and SWDM were compared. ABAQUS subroutine was used to simulate the weld failure process, the influence of joint geometry parameters on weld bearing capacity was analyzed. The results show that the fracture load predicted by SWDM is lower than that predicted by VGM. The stress state of fracture point is a trend change from axisymmetric tensile or compressive state to plane strain state. By introducing the Lode angle parameter, SWDM can accurately simulate the damage accumulation of joints under different stress states. The prediction accuracy is higher than that of VGM, and the applicability is better. The cracking of the weld starts at the saddle point and develops rapidly to the crown point, leading to the destruction of the joint. When the wall thickness of branch pipe and main pipe is constant, the larger the outer diameter ratio of branch pipe and main pipe and the diameter thickness ratio of main pipe, the lower the bearing capacity of weld. The calculation formula of weld bearing capacity in Standard for design of steel structures(GB 50017—2017) does not consider the influence of uneven stress of weld, and the calculation results will be unsafe.
Keywords: tubular joint; stress-weighted damage model; void growth model; fracture prediction model; weld bearing capacity
539
0
0