考虑剪切变形影响的空间管桁架组合梁挠度计算与分析  

Calculation and analysis on deflection of spatial tube truss composite beam under the influence of shear deformation

作　　者：陈建兵[1,2] 李夏元[1] 陈荣[1] 苏坤[1] 

机构地区：[1]苏州科技学院土木工程学院,苏州215011 [2]江苏省结构工程重点实验室,苏州215011

出　　处：《建筑结构》2014年第22期45-51,共7页Building Structure

基　　金：江苏省结构工程重点实验室资助课题(ZD1102)

摘　　要：为研究新型空间管桁架组合结构的变形特点,将空间管桁架组合梁弯曲受力行为分解为等效空腹虚拟梁的弯曲作用和腹杆组成的虚拟桁架作用。利用虚功原理建立了考虑空腹式腹杆剪切变形影响的挠度计算公式,并采用模型梁加载试验与有限元分析法对计算挠度进行了对比分析。结果表明:剪切变形产生的挠度为计算总挠度的52%,为弯曲作用产生的计算挠度的1.07倍;在各级荷载作用下,考虑剪切变形影响的计算挠度与试验、有限元结果吻合较好,平均偏差分别为5%和2%,试验值与有限元计算值的平均偏差为2%;实测结果验证了计算公式的正确性和有限元模型的合理性。文中建立的挠度计算公式为此类结构在弹性状态时的挠度计算提供了一种准确的简化计算方法。To study the deformation characteristic of the new spatial tube truss composite structure,the bending behavior of spatial tube truss composite beam was simplified into flexion of equivalent virtual hollow beam and effect of virtual truss with web members. The virtual work principle was applied to establish the deflection formula under the influence of shear deformation of hollow web,besides,the results were analyzed and compared respectively with the test on beam model and finite element mathematical model. The results show that shear deformation accounts for 52 percent of all deflection,which means it is 1. 07 times that of deflection under the flexion; at the state of all stepwise loadings,the calculated results under the influence of shear deformation from formula agree with the experimental results and finite element results well,the average difference is 5 percent and 2 percent respectively,while the average difference of the experimental results and finite element results is 2 percent; the measured results verify the validity of the computational formula and the rationality of the finite element model. The deflection calculation formula provides an accurate and simplified calculation method for such structure on the state of elasticity.

关 键 词：空间桁架 钢-混凝土组合梁 挠度 剪切变形 计算公式 

分 类 号：TU398[建筑科学—结构工程]