钢管桁架节点效率系数研究  

Study on joint efficiency coefficient of steel tubular truss

作　　者：马印平[1] 刘永健[1] 王琨[1] 马天宇 MA Yinping;LIU Yongjian;WANG Kun;MA Tianyu(School of Highway,Chang’an University,Xi’an 710064,China)

机构地区：[1]长安大学公路学院,陕西西安710064

出　　处：《建筑结构学报》2022年第7期205-218,共14页Journal of Building Structures

基　　金：中央高校基本科研业务费专项(300102219310);国家重点研发计划(2016YFC0701202);国家自然科学基金项目(51738068)。

摘　　要：为对桁架节点受力性能及其与桁架整体力学性能的相互关系进行研究,基于已有的桁架节点承载力及刚度计算方法,得到了桁架节点承载力效率系数和刚度效率系数两个无量纲参数。其中节点承载力效率系数定义为腹杆轴力作用下节点承载力与腹杆发生强度破坏承载力的比值,节点刚度效率系数则定义为腹杆轴力作用下节点轴向刚度与腹杆线刚度的比值。在此基础上,给出了考虑节点力学性能影响的钢管桁架抗弯刚度及承载力简化计算方法,对工程常见参数范围内的矩形及圆形钢管桁架节点承载力、刚度效率系数进行参数分析。结果表明:桁架节点刚度及承载力效率系数实质上反映了钢管桁架节点与腹杆力学性能的量化相互关系,其可在桁架层面对不同类型的节点力学性能进行比较,还可以作为节点力学性能评估和方案优化设计的通用评价指标;依据节点承载力、刚度效率系数可对钢管桁架抗弯刚度及承载力进行快速、准确地估算;为避免桁架由于节点失效过早发生破坏,建议将节点承载力效率系数大于0.8且节点刚度效率系数大于5的桁架定义为满足“强节点弱构件”设计理念的桁架。In order to study the mechanical properties of joint and its relationship with the mechanical properties of truss,based on the existing calculating methods for bearing capacity and stiffness of truss joint,two dimensionless parameters,the capacity efficiency coefficient and the stiffness efficiency coefficient,were obtained.The capacity efficiency coefficient is defined as the ratio of bearing capacity of joint under axial force to bearing capacity of brace when strength failure occurs.The stiffness efficiency coefficient is defined as the ratio of axial stiffness of joint to the linear stiffness of brace under axial load.A simplified calculating method of flexural stiffness and capacity of steel tube truss considering the influence of mechanical properties of joint was given.Meanwhile,the joint efficiency coefficients of rectangular and circular steel tube within the range of common engineering parameters were analyzed.The results show that the above two efficiency coefficients essentially explain the quantitative relationship between the mechanical properties of steel tube truss joint and brace.The joint efficiency coefficients can be applied in comparisons between different types of joint at the truss level and it also can be used as a general evaluation index for mechanical properties evaluation and scheme optimization.According to the joint efficiency coefficients,the flexural stiffness and bearing capacity of truss can be predicted accurately and rapidly.In order to avoid the premature failure of truss due to joint failure,the design conception of‘strong joint and weak member’for truss is defined as the capacity efficiency coefficient greater than 0.8 and the stiffness efficiency coefficient greater than five.

关 键 词：钢管桁架节点 节点效率系数 节点轴向刚度 节点承载力 力学性能评估 

分 类 号：U441[建筑科学—桥梁与隧道工程]