带缺陷T形截面叠合梁抗弯性能研究  

Study on flexural performance of T-shaped composite beams with defects

作　　者：冯庆兴 林皇诚 龚顺风[2] FENG Qingxing;LIN Huangcheng;GONG Shunfeng(School of Civil Engineering and Architecture,Zhejiang University of Science&Technology,Hangzhou 310023,Zhejiang,China;Institute of Structural Engineering,Zhejiang University,Hangzhou 310058,Zhejiang,China)

机构地区：[1]浙江科技学院土木与建筑工程学院,浙江杭州310023 [2]浙江大学结构工程研究所,浙江杭州310058

出　　处：《建筑科学与工程学报》2023年第4期70-79,共10页Journal of Architecture and Civil Engineering

基　　金：浙江省重点研发计划项目(2018C03033-1)。

摘　　要：为研究带缺陷T形截面叠合梁抗弯性能,探究缺陷对其抗弯性能的影响,考虑不同缺陷总长、缺陷位置和现浇厚度,对3根带缺陷T形截面叠合梁和1根对比梁进行了三分点单调荷载下的足尺梁试验,并利用ABAQUS有限元软件建立数值模型对试验结果进行验证分析。结果表明:带缺陷T形截面叠合梁发生受弯破坏时,叠合面的黏结性能良好,无明显滑移现象;缺陷对叠合梁试件承载力的折减约为3%,影响较小,但对延性的影响稍大;缺陷削减了截面刚度,容易在梁底引起更多的次生裂缝;在一定缺陷总长范围内,缺陷对抗弯承载力的影响较小,超过该长度时,缺陷总长的增加对峰值荷载的削弱作用将变得显著;改变缺陷位置会导致实际黏结抗力大小发生改变,对承载能力的影响也随之变化,当缺陷处于剪力较大位置时对抗弯性能的影响较大;在一定范围内提高现浇厚度可以增强叠合梁的承载能力,缺陷产生的影响也随之降低,但超过一定值后,裂缝较早地开展至结构薄弱面,叠合梁承载能力降低,缺陷对叠合梁抗弯性能的削弱作用也将增大。In order to study the flexural performance of T-shaped composite beam with defects and the effect of defects on flexural performance,considering different defect total length,defect position and cast-in-place thickness,full-scale tests of three T-shaped composite beam with defects and one comparison beam were carried out under monotonic load.The numerical model was established by ABAQUS finite element software to verify the test results.The results show that the bonding performance of the laminated surface is good and there is no obvious slip when the T-shaped composite beam with defect occurs bending failure.The reduction of the bearing capacity of the composite beam specimen is about 3%,which is less affected,but the effect on the ductility is slightly larger.The defects reduce the stiffness of the section,which is easy to cause more secondary cracks at the beam bottom.Within a certain range of the defect total length,the defect has little effect on the flexural bearing capacity.But when the defect total length exceeds certain value,the weakening effect on the peak load will become significant.Changing the defect position will lead to the change of the actual bond resistance,and the influence on the bearing capacity will also change.When the defect is in the position of larger shear force,the effect of the defect on the flexural performance is great.Increasing the cast-in-place thickness within a certain range can enhance the bearing capacity of the composite beam,and the influence of the defect is also reduced.However,after exceeding a certain value,the bearing capacity of the composite beam will be decreased as the cracks developing to the weak layer earlier,and the weakening effect of the defect on the bending resistance of the composite beam will also increase.

关 键 词：叠合梁 缺陷 抗弯性能 足尺梁试验 内聚力模型 参数分析 峰值荷载 不利位置 

分 类 号：TU375[建筑科学—结构工程]