冷弯薄壁型钢连接件力学性能研究

发布时间：2018-04-01 21:43

本文选题：冷弯薄壁型钢-覆面板材自攻螺钉连接件　切入点：抗剪承载力　出处：《东南大学》2015年硕士论文

【摘要】：冷弯薄壁型钢结构体系源于传统的木结构,是一种富有特色的新型结构体系,具有高性能、轻质、产业化、环保等显著特点。此类结构体系在国外低层住宅中已得到广泛应用,在我国应用起步较晚。自攻螺钉连接是该结构体系中一种主要的连接形式。本文通过两种不同试验装置对冷弯薄壁型钢·覆面板材白攻螺钉连接的力学性能进行试验研究,拟合出其骨架曲线模型和滞回模型,并运用有限元软件对连接件单调加载工况进行了数值模拟。主要内容及结论如下：首先,通过材性试验得到了四种覆面板材的弹性模量、静曲强度和泊松比：通过238组连接件的抗剪试验研究,探讨了试验装置、覆面板材类型(石膏板、玻镁板、OSB板和硅酸钙板)、螺钉端距、钢龙骨厚度、螺钉直径、加载方式(单调拉／压和低周往复加载)以及板材布置方向对冷弯薄壁型钢自攻螺钉连接件力学性能及破坏模式的影响。试验结果表明：对于单调加载工况,两种试验装置下连接件的破坏模式相同,且除钢龙骨-OSB板连接件外其余三种连接件的峰值荷载误差均在±15%范围内,各参数呈现相同的规律；但采用多根螺钉连接件加载装置时,得到的连接件峰值变形普遍较大,可通过减小垫板与U型龙骨腹板的宽度差值尽量减小此误差；四种连接件在单调拉伸时均为板材承压破坏,均未出现螺钉剪断,低周往复加载时,钢龙骨-OSB板和钢龙骨-硅酸钙板连接件会出现螺钉弯曲甚至螺钉被剪断的现象；板材类型、螺钉端距对连接件力学性能影响明显,随螺钉端距增大,连接件承载力相应增大；龙骨厚度和螺钉直径对连接件力学性能的影响较小,且与覆面板材种类相关；钢龙骨-OSB板与钢龙骨-MgO板连接件受板材方向(指平行板材长边或短边方向截取板材)影响不大：钢龙骨-GWB板和钢龙骨-CSB板连接件沿长边方向截取板材,其连接件承载力较短边分别提高了10%和20%-50%；低周往复加载时,连接件荷载-变形曲线存在明显“捏拢效应”,较之单调拉神连接件抗剪承载力下降4%～18%,且边距越大,降幅越突出,故而需对单调加载所得承载力折减后再用于工程设计。然后,通过对试验数据的处理和分析,并借鉴木结构钉子连接的几种常见恢复力模型,得到了冷弯薄壁型钢-覆面板材自攻螺钉连接件的恢复力模型,包括单调加载时连接件的"Foschi"指数型骨架曲线模型和低周往复加载时连接件的Pivot定点指向型滞回模型。最后,采用ANSYS有限元程序对冷弯薄壁型钢-覆面板材自攻螺钉连接件单调加载工况的力学性能进行了数值模拟分析。模型的建立考虑了材料非线性及接触非线性。采用Solid45单元模拟连接件及自攻螺钉,在连接件螺钉孔部位设置接触单元,并对自攻螺钉进行了合理简化,同时忽略自攻螺钉旋入时产生的预紧力。对于硅酸钙板(CSB板)这样的脆性覆面板材本文采用Solid45单元和Solid65单元分别进行实体建模,前者模拟此类连接件的荷载-变形曲线,后者模拟其裂缝开展,二者互为补充。将有限元模拟所得破坏模式、荷载-变形曲线走势、连接件的承载力及各因素(包括板材布设方向、螺钉直径、龙骨厚度和螺钉端距等)对连接件性能的影响与试验结果对比分析,证实有限元模型准确有效。
[Abstract]:The source of cold-formed steel structure to the traditional wooden structure, is a kind of new structure characteristic, has the advantages of high performance, lightweight, industrialization, environmental protection and other notable features. This kind of structure system has been widely used in low rise residential, relatively late in our application of self tapping screw connection is a start. The main connection form of the structural system. In this paper, through two different test device of cold-formed steel cladding plate, connecting white tapping screws mechanical properties of experimental research, the fitting model of skeleton curve and hysteretic model, and use the finite element software to simulate the monotonic loading conditions. The main connection the contents and conclusions are as follows: firstly, through the material test results of the elastic modulus of the four cladding plate, static bending strength and Poisson's ratio by shearing test on 238 groups of joints, discusses the test device, Cover plate type (gypsum board, glass magnesium board, OSB board and calcium silicate board), screw end distance, thickness, diameter of the screw steel keel, loading mode (monotonic tension / pressure and low cyclic loading effects) and sheet arrangement direction of connector mechanical performance and failure mode of cold-formed steel tapping screws. The test results show that the monotonic loading conditions, the same failure mode of connection of two kinds of test device, and in addition to the peak load error of the other three types of connectors of steel keel plate were -OSB + 15% in the range of each parameter has the same rule; but adopts a plurality of screw loading device, get the connector peak deformation is generally larger, can reduce the error by reducing the width difference plate and U type keel plate; four kinds of joints under monotonic tensile were plate bearing damage without screw cut, low Zhou Wangfu When loading, -OSB steel keel plate and steel keel - calcium silicate plate will appear even cut screw screw bending phenomenon; plate type, screw end distance obviously on the mechanical properties of joints, with the screw end distance increases, a corresponding increase in the bearing capacity of joints; keel thickness and diameter of the screw has little effect on the connecting piece the mechanical properties, and cladding plate types; steel plate and steel keel keel -OSB -MgO plate by plate direction (parallel plate refers to the long side or short side direction interception plate): -GWB has little effect on steel keel plate and steel keel -CSB board connector interception along the long side direction of the plate, the connecting piece is the short side was increased by 10% and 20%-50% capacity; low cyclic loading, the load deformation curve of joints and obvious "pinching effect", a monotonic shear capacity of connections would fall from 4% to 18%, and the margin of the greater decline More prominent, therefore need reduction after used for engineering design on the bearing capacity of the monotonic loading. Then, through the test data processing and analysis, and draw some wooden nail connection common restoring force model, the cold-formed steel cladding plate self tapping screw of the restoring force model, including monotonic loading when the connecting piece of the "Foschi" type index skeleton curve model and low cyclic loading when the connection point Pivot oriented hysteretic model. Finally, the mechanical properties of cold-formed steel cladding plate - monotonic loading condition of self tapping screw is simulated and analyzed by using the finite element program ANSYS model considering. The material nonlinearity and contact nonlinearity. Using Solid45 element and self tapping screws, contact element is set on the connecting piece and the screw hole, tapping screws are reasonably simplified, At the same time, ignoring the pretightening force self tapping screws screwed in. The calcium silicate board (CSB board) that the Solid45 cladding plate brittle unit and Solid65 unit for solid modeling, the simulation of deformation curve of load - such connections, which simulate the crack development, the two complement each other. The Co. the element failure mode, load deformation curve, bearing capacity of joints and the various factors (including the sheet layout direction, screw diameter, keel thickness and screw end distance) influence on the connection performance and test result analysis, confirmed that the finite element model is accurate and effective.

【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU392.1

【参考文献】