支主管夹角对X形圆钢管节点轴向传力的影响  

Effect of Brace-to-Chord Angle on Performance of Unstiffened Circular Hollow Section X-Joints under Brace Axial Force

作　　者：赵必大 李克 刘成清[2] 吴剑国[1] ZHAO Bida;LI Ke;LIU Chengqing;WU Jianguo(College of Civil Engineering,Zhejiang University of Technology,Hangzhou 310023,China;School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]浙江工业大学土木工程学院,浙江杭州310023 [2]西南交通大学土木工程学院,四川成都610031

出　　处：《西南交通大学学报》2021年第2期282-288,共7页Journal of Southwest Jiaotong University

基　　金：国家自然科学基金(51778538);国家留学基金委项目(201707005100)。

摘　　要：为了研究支主管夹角对X形圆钢管相贯节点轴向受力性能的影响,进行相关试验来校验有限元模型,以有限元为手段分析了支主管夹角对X形节点在支管轴力作用下的传力特性和承载力的影响;根据有限元参数分析结果,对支主管夹角较小的节点的承载力提出了改进建议.研究结果表明:节点试件的破坏模式为相贯线附近主管管壁局部屈曲;当支主管非正交但夹角大于60°时,节点的传力特性与支主管正交节点的相近,符合Togo模型的假定,现行规范中的夹角正弦的倒数项能精准地反映夹角对节点承载力的影响;但当节点的支主管夹角小于45°时,其传力特性与Togo模型的假定有较大的差异,夹角正弦的倒数也低估了支主管夹角对节点承载力的提高,对于夹角接近30°的节点甚至低估了30%;因此建议当夹角小于45°时,在规范已有的节点承载力计算式的基础上乘以修正系数.In order to study the effect of brace-to-chord angle(BCA)on the performance of unstiffened circular hollow section(CHS)X-joints under brace axial force,experimental test was carried out to verified finite element(FE)model.Then FE parameter analysis were used to study the effect of BCA on the stress transfer and bearing capacity of the X-joints under brace axial force,and the capacity prediction accuracy of the X-joints with small BCA was improved.The results show that the failure pattern of test is local buckling of chord wall near brace-tochord intersection.The incline X-joints(brace-to-chord non-orthogonal)with BCA greater than 60°have the similar stress transfer characteristic to that of the brace-to-chord orthogonal X-joints,which is consistent with the assumption of the Togo model.Moreover,the reciprocal of the sine of BCA(RSBCA)in the current specification can accurately reflect the influence of BCA on the capacity.However,the stress transfer characteristics of the incline X-joints with BCA less than 45°are quite different from the assumption of the Togo model,and RSBCA underestimates the beneficial effect of BCA on the capacity of these X-joints(even 30%for the X-joint with BCA near to 30°).Hence,it is recommended to multiply a correction coefficient on the existing capacity prediction formula of these CHS X-joints with BCA less than 45°,to improve the prediction accuracy.

关 键 词：X形圆钢管相贯节点 支主管夹角 传力特性 节点承载力 有限元参数化分析 局部屈曲破坏 

分 类 号：TU392.3[建筑科学—结构工程]