钢桁梁工字钢腹杆承压试验及模型修正研究  

Study on Bearing Test and Model Updating of I-steel Web Member of Steel Truss Beam

作　　者：曾志远 何雄君[1] 仵卫伟 ZENG Zhi-yuan;HE Xiong-jun;WU Wei-wei(School of Transportation and Logistics Engineering,Wuhan University of Technology,Wuhan 430063,China)

机构地区：[1]武汉理工大学交通与物流工程学院,武汉430063

出　　处：《武汉理工大学学报》2022年第5期68-75,共8页Journal of Wuhan University of Technology

基　　金：国家自然科学基金(51178361);湖北省交通运输厅科技项目(2018-422-1-2)。

摘　　要：为探究白洋长江大桥钢桁梁的最不利腹杆的破坏形式与力学特性,以大桥的最不利节段处的钢桁梁工字钢腹杆为研究对象,对设计制作的畸变缩尺模型试件进行轴压承载能力试验,采用基于试验结果的模型修正方法对有限元模型进行修正,得到与试验接近的计算模型,借此探讨初始缺陷对钢腹杆失稳的影响。结果表明:轴向压力作用下,试件在200k N时,跨中截面处屈曲失稳,翼缘板向内凹陷。初始有限元模型的模拟结果与试验结果在屈曲临界力、荷载-位移曲线等方面有一定的差距,综合考虑各影响因素,利用试验结果对初始模型进行修正,修正后的模型更符合实际,修正后参数与测量结果接近。利用修正后的模型对初弯曲、初偏心、残余应力等因素进行分析,残余应力及初弯曲对工字钢腹杆的失稳影响较大。In order to explore the failure form and mechanical characteristics of the most unfavorable web members of steel truss beam of Baiyang Yangtze River Bridge,the I-shaped web member of steel truss beam at the most unfavorable section of the bridge was taken as the research object,and the axial compression bearing capacity test of the designed and manufactured distorted scale model specimen was carried out.The finite element model was updated by the model updating method based on the test results,and the calculation model close to the test was obtained,so as to explore the influence of initial defects on the instability of the web members.The test results show that,under axial pressure,when the specimen is at 200 kN,it will buckle and lose stability at the mid-span section,and the flange plate will sag inward.There is a certain gap between the simulation results of the initial finite element model and the test results in terms of buckling critical force,load-displacement curve,etc.Considering all the influencing factors comprehensively,the initial model is updated by using the test results.The updated model is more realistic,and the updated parameters are close to the measured results.The updated model used to analyze the factors such as initial bending,initial eccentricity and residual stress.The residual stress and initial bending have great influence on the instability of I-steel web members.

关 键 词：钢桁梁 工字钢腹杆 承压能力 模型修正 初始缺陷 

分 类 号：U442.5[建筑科学—桥梁与隧道工程]