门式刚架二次包浇混凝土钢柱脚节点性能的有限元分析  

Finite Element Analysis of Joint Performance of Secondary Pouring Concrete Pipe Steel Column Based on Portal Frame Structure

作　　者：刘礼正 刘磊 郜子轩 任杰德 梁宗敏[1] Lizheng Liu;Lei Liu;Zixuan Gao;Jiede Ren;Zongmin Liang(School of Water Resources and Civil Engineering,China Agricultural University,Beijing 100083,China;Suzhou Zhaorui Real Estate Development Co.,Ltd.,Suzhou 215156,China)

机构地区：[1]中国农业大学水利与土木工程学院,北京100083 [2]苏州兆瑞房地产开发有限公司,江苏苏州215156

出　　处：《钢结构（中英文）》2022年第6期1-8,共8页Steel Construction（Chinese & English）

基　　金：国家重点研发项目(2018YFD0500700)。

摘　　要：现代规模化畜禽养殖舍、屠宰场、农产品加工车间等建筑常采用门式刚架轻型钢结构体系,钢柱脚往往采用简易外露式柱脚。这类建筑室内湿度较大,有时还有一定的腐蚀性,出于对钢柱脚的保护和提高结构耐久性的目的,常采用二次包浇混凝土的做法。因包浇混凝土通常为素混凝土,因此结构受力分析与设计中,忽略了二次包浇混凝土对节点抗弯承载力、转动刚度以及延性的影响,使分析结果与实际工况有一定差异,可能带来设计上的浪费或安全隐患。因此,以此类建筑的轻型钢结构为工程背景,针对门式刚架二次包浇混凝土钢柱脚节点,在轴压和弯矩共同作用下,考虑100,150,200 mm三种包浇混凝土厚度进行分析,发现包浇混凝土能明显提升柱脚的抗弯承载力和延性,且厚度越大,提升幅度越大,同时对转动刚度也有一定提高。进一步,在包浇混凝土厚度150 mm时,考虑在包浇混凝土内不加钢筋网、加一层钢筋网和加两层钢筋网三种情况,以及在包浇混凝土段加4 mm和6 mm外包钢的两种情况,采用通用商业有限元软件模拟分析,共对比了8种情况对钢柱脚受力性能的影响,重点关注抗弯承载力、转动刚度与延性。结果表明:包浇混凝土受拉侧与受压侧均存在塑性应力集中,受压侧下部较上部更为集中,受拉侧上部较下部更集中;随着包浇混凝土厚度的增加,对柱脚的抗弯承载力和延性系数的提升越来越大;两种钢筋网的加入对转动刚度均有一定的提升,其中铺设两层钢筋网的提升效果更为明显,上部附加一层钢筋网使得包浇混凝土的上部塑性应变区域变小;上、下部各附加一层钢筋网使得混凝土上、下部的塑性应变区域均变小,说明钢筋网对混凝土提供了有效约束,可延缓包浇混凝土的裂缝开展;上、下两层钢筋网均承担一定的拉应力,尤其上部钢筋网承担更大的拉应力;包浇混凝土Modern large-scale livestock and poultry breeding houses,slaughterhouses,agricultural products processing workshops and other buildings often adopt light-weight steel portal frame structure systems,steel column base often adopts simple exposed column base.This kind of buildings have high indoor humidity and a certain corrosive sometimes,in order to protect the steel column base and improve the durability of the structure,the practice of secondary pouring concrete is often used.Because the pouring concrete is usually plain concrete,the influence of the secondary pouring concrete on the bending capacity,rotational stiffness and ductility is often ignored in the structural analysis and design,which makes the analysis results differ from the actual working conditions to a certain extent,and may bring about waste in design or hidden safety hazards.Therefore,taking the light-weight steel structure of this kind of buildings as the engineering background,considering the three types of pouring concrete thickness of 100 mm,150 mm and 200 mm under the action of axial compression and bending moment,it is found that the pouring concrete can obviously improve the bending capacity and ductility of the column base,and the bigger the thickness is,the bigger the improvement is.At the same time,there is a certain law of increasing the rotational stiffness.Further in the package thickness under the condition of 150 mm,considering the pouring concrete without reinforcement net,add a layer of reinforcement net and add two layers of reinforcement net three scenarios,in pouring concrete section 4 mm and 6 mm outer clad steel of two situations,with the general commercial finite element software simulation,it compared the eight kinds of conditions on the properties of the steel column base mechanical performance,the emphasis was placed on the bending capacity,rotational stiffness and ductility.The results show that the plastic stress concentration exists in the tensile side and the compression side of the pouring concrete,the lower part o

关 键 词：钢柱脚 二次包浇 承载力 延性 转动刚度 

分 类 号：TU391[建筑科学—结构工程]