【作者】 马广阅；

【导师】 彭少民；

【作者基本信息】 武汉理工大学 ， 结构工程， 2010， 博士

【摘要】 关于冷弯薄壁型钢结构的研究及应用在国内外已经十分广泛,并取得一定的成果。当然,仍有些亟待解决的问题,如各国规范中给出的截面特性均缺少屈曲理论应用所需要的扭转截面特性参数,如圣维南扭转常数J,扭曲扭转(或翘曲)常数Cw,剪切轴心的位置(x0),有效截面模量Se,整体屈曲、局部屈曲、畸变屈曲的相关性等,都没有非常明确、通用的设计计算方法,工程设计中很难去求解。目前冷弯薄壁型钢住宅结构形式有很多种,如北美、日本、澳大利亚等国选用的材料和截面形式也不尽相同。但却大同小异,基本上按照一定的模数间距布置钢龙骨、支撑体系,骨架两侧覆板和保温隔热材料以及面层装饰材料,形成可靠的“密肋型结构体系”值得一提的是澳大利亚迈特冷弯薄壁型钢结构住宅系统,有一个显著特点即高强度、超薄壁。所有构件均是标准截面,如杆件为带卷边的C形截面杆,其尺寸均为40×90,厚度从0.55mm到1.15mm不等。可以通过分析一个杆件,即可概括结构构件的受力特性。高强度、超薄壁构件的应用可大为减轻结构自重,但又带来了新的问题,如材料性能、畸变屈曲的确定、各种屈曲模式的相关性等。我国现行《冷弯薄壁型钢结构技术规范》规定材料的强度最高位Q345,主要承重结构构件的壁厚不宜小于2mm。表明这种高强、超薄壁结构无论结构设计计算或施工组装均有其自身的鲜明特征。为解决工程应用中的迫切需要,本文试图通过试验研究、分析,并通过系列理论推导和仿真分析,推荐符合工程师应用的公式,方便快捷实用的表格。本文选用上海宝钢蓝璀公司生产的G550级高强钢材进行材性试验,得出了G550级钢材的应力-应变特性,给出了试件材料的主要材性指标。通过不同连接形式、不同抽芯铆钉的连接试件的多组试验,研究相应的受力特征、破坏形态和极限承载力,并经理论分析计算结果进行对比,获得了高强超薄壁冷弯型钢结构中拉铆钉连接的破坏模式和承载力计算公式。通过理论推导,得出标准截面构件不同长度、不同受力情况可能的屈曲模式、屈曲应力和屈曲后强度,给出了复杂截面构件的屈曲应力。通过三榀桁架梁的试验和详尽分析,以及多榀桁架梁的有限元分析,明确了桁架梁的破坏过程以及破坏形态,给出了不同跨度、不同高度桁架梁的容许荷载表格。通过竖向荷载和水平荷载同时作用下K型支撑墙架的试验,分析研究该墙架的破坏形态、受力特征以及承载能力。实验表明墙架柱首先出现畸变屈曲,然后柱脚出现受压破坏或受拉破坏。进而通过试验观察、分析总结了墙架承载能力的验算公式。以上研究成果,部分纳入了湖北省地方标准《低层住宅冷弯薄壁型钢结构技术规程》,本人有幸参编。这也是国内首次颁布针对高强超薄壁结构的技术标准。更多还原

【Abstract】 Although the research and application of the cold-formed thin-walled steel structures has been extended widely and the remarkable achievements in this field have been gained, some key problems have not been solved. As known, some sectional characteristic parameters needed by the analysis of critical buckling stress are not clearly definited in the specifications, including the Saint-Venant torsion constant of the cross section (J), torsional warping constant of the cross section (Cw), location of shear axis (x0), elastic modulus for effective section calculated by a stress relative to the extreme compression strain (Se), and the correlativity between global buckling, local buckling and distortional buckling. It is very difficult to calculate above parameters definitely in engineering design.At present, the cold-formed thin wall steel structures for residential buildings have various types. In the North America, Japan and Australia, the steel materials, section form of members and structural system are different. Even so, they are of similar composition of the structure, in which the steel keels are arranged basically according to-certain module spacing, different support systems are appranged between the steel keels, the structure-plate, the heat preservation thermal insulation material, as well as the surface layer decoration material are installed in turn on the both sides of keel skeletons. All these components forms an extremely reliable "structural system of the dense ribs".The cold-formed thin wall steel structures applied to residential building systems in Australia are different from that of other systems. They have two remarkable features:high strength of material and ultra thin wall of member section. All members have uniform cross section that is common C-shape section with the sectional sizes of 40mm×90mm and the wall thickness ranged from 0.55mm to 1.15mm. The advantage of using uniform member sections is that the mechanical behaviors of structural members can be summarized through the analysis of an element.The high strength thin wall component brings new problems, such as material properties, buckling distortion and the relevant of all buckling mode and so on.In order to solve urgent need in the project application, this article tries to build design formula and form which can be easily and conveniently used through the experimental study, theoretical and the simulation analysis. In this paper, G550 high-strength steel which Shanghai Baoshan Iron and Steel LanCui Co. produced was used. The stress-strain relationship of grade G550 steel and other properties have been obtained.High-strength cold-formed thin wall steel structure pull rivet failure mode and bearing capacity formula have been obtained through different connected forms, different diameter blind rivets to connect multiple sets of test specimens, by their own force characteristics, failure modes and ultimate strength, and the theoretical analysis and calculation results were compared, the first time in our country are given.Through accurate experiment and exhaustive analysis which carries on to three girder trusses, as well as 29 girder truss finite element analysis, gave allowed load form about different span, different girder truss given for the first time in our country。Through K-brace wall framing test under both vertical load and horizontal load, the wall framing failure mode, mechanical characteristics and bearing capacity have been studied. Wall frame column local buckling occurs first, then column foot appears damaged or destroyed by the pull and pressure. The calculation and analysis of the ultimate bearing capacity of the wall frame is summarized.更多还原