Equivalent thickness of cold-formed thin-walled channel sections with perforated webs under compression

Cold-formed thin-walled channel sections with perforated webs (thermal studs) are widely used in external wall panels in cold regions to reduce the cold bridging effect. However, no design method appears to be available for this type of structure. A possible method is to convert the perforated web of a thermal stud into a solid one with a reduced thickness (which is referred to as the equivalent thickness) and then adopt an existing design method for solid sections (e.g. EN 1993-1-3). This paper presents the development of a method to calculate the equivalent web thickness. The equivalent thickness calculation equation is based on regression analysis of a large number of finite element simulation results of elastic local buckling strength of perforated plates under compression, considering the effects of a number of different design variables such as plate depth, thickness, perforation patterns and dimensions of the plate. The FE simulations were carried out using a general FE software. This study suggests that the equivalent thickness is mainly related to the plate width to thickness ratio, the total width of perforation at the critical section and the width of the perforation zone (total plate width between the first and last perforation). A regression equation has been proposed to relate the equivalent thickness to these parameters. To demonstrate the validity of the proposed equivalent thickness method, the compression strengths of a large range of perforated columns have been simulated by using either the original perforated sections or the equivalent solid section; and a comparison of the simulation results shows good agreement between the two sets of results.     

Study of partially encased composite beams with innovative position of stud bolts

In this article, static behavior of three partially encased composite beams under flexural condition is investigated in the context of studying some alternative positions for the headed studs. Shear resistance between the I-shaped beam and the concrete was provided by headed studs in two positions: vertically welded on the bottom flange and horizontally welded on the faces of the web. Experimental results show that the headed studs provide the composite action and increase the bending strength. The most remarkable position seems to be the headed studs vertically welded on the bottom flange. An analytical method to estimate the bending capacity of the encased beams is also proposed, giving a good prediction of the experimental results     

锈蚀栓钉连接件力学性能试验研究

为了解钢-混组合梁的栓钉连接件发生锈蚀后的静力工作性能,进行了4组栓钉试件的推出试验.首先通过人工电化学快速锈蚀方法使试件中的栓钉达到预定锈蚀状况,然后进行静载破坏试验,通过试验结果分析不同锈蚀状况对栓钉连接件力学性能的影响.结果表明:栓钉钉杆尤其是靠近结合面处发生锈蚀时,其极限承载力降低最大达到18％,相同荷载作用下...     

住宅建筑的轻钢框结构

采用轻钢构件、石膏板和矿棉板制造的建筑系统在美国、澳大利亚和日本应用广泛,并正在逐渐占据欧洲国家的市场。这类系统通常具有承重墙,轻型钢带或混凝土楼板,适用于工业化生产和高效的建造过程。文中提供有这些构件和系统的实例。中低层建筑采用的墙体主要抵抗风荷载等水平作用。自20世纪70年代起,在瑞士和芬兰开始普及该类型木结构房屋。本文介绍了在多层建筑中采用单层石膏板作为墙体的传统设计模式,后由于防火需要将墙体改用双层板建造。     

Light steel framing for residential buildings

Building systems with light steel members, gypsum plasterboards and mineral wool have a wide spread use in the US, Australia and Japan and are gaining market in some European countries. The systems have often load-bearing walls and the floors may be of lightweight steel profiles or concrete. Such systems are suited for industrial production and can contribute to a more efficient building process. Examples of components and systems are given in the paper. For low and medium rise buildings it is natural to use the walls as stabilising for horizontal loads from wind and imperfections. In Sweden and Finland this has been common practice for single-family timber houses since the 1970s. The paper describes the traditional design model for walls with single-layer gypsum plasterboards and an extension to double layers, which are needed for fire protection in multi-storey buildings.     

冷弯型钢房屋墙体立柱临界屈曲荷载能量解

冷弯薄壁型钢低层住宅房屋体系的墙体一般由墙体密立柱、墙面围护材料组成 墙面材料不仅是建筑的需要 ,同时也能在一定程度上对墙体立柱提供有效的支承作用 通过简化推导 ,建立起了考虑墙板的支承效应时墙体立柱的力学模型 ,并在弹性范围内 ,分别利用Rayleigh Ritz法推导出了墙体立柱两端简支、两端固定、一端固定一端自由和一端简支一端固定等 4种典型边界条件下墙体立柱的整体屈曲临界荷载 ,并将其转化成为常规形式的表达式 ,可供设计、研究参考     

Modular Mountain Retreat

This prefabricated tree house in the Catskill Mountains two hours north of New York City nestles into its evergreen site. Designed by Joseph Tanney and Robert Luntz of Resolution: 4 Architecture, it combines two types of existing prefabricated components and two prototypes that the architects have developed out of their own research. Jayne Merkel explains how the design supports the owner's rugged outdoor lifestyle with an airy refined retreat that is tailored to the bachelor art director's particular needs. Copyright © 2007 John Wiley & Sons, Ltd.     

钢梁与包覆RC箱型钢柱之梁柱接头耐震性能研究

本研究进行两组“大尺寸梁柱接头”之反复载重试验,以探讨其力学行为与耐震性能。本研究之试体采用钢梁与“受钢筋混凝土包覆之箱型钢柱（简称包覆箱型钢柱或SRC柱）”接合之梁柱接头。此种钢梁与SRC柱接合之构造的主要特点,在于利用SRC柱之劲度、防火与抗压强度方面的长处,又可以发挥钢梁在韧性与施工便捷方面之优点。本研究之试体均符合“强柱弱梁”之原则且梁柱接头区之标称剪力强度均大于该区之需求剪力强度,试体之断面配置均符合台湾SRC设计规范之要求。本研究探讨之重点包含：（1）此种新型梁柱接头之钢梁塑性铰的发展情肜,（2）梁柱接头区混凝土之开裂状况,（3）配置剪力钉对梁柱接头韧性之影响。实验结果显示,由于SRC柱内之箱型钢管断面在X与Y向各有两片腹板,故可以提供梁柱接头区充分的剪力强度,并可抑制接头区的剪力变形,使接头区之混凝土保持良好状态,并无明显开裂之情形,进而确保插入SRC柱的钢梁受到接头区之钢筋混凝土有效的束制,使得钢梁的塑性铰可以远离焊道,最终在SRC柱之混凝土面外约15cm处发展出稳定且充分的塑性变形。换言之,SRC柱接头区的钢筋混凝土具有保护钢骨梁柱接头焊道的功能,该区的钢筋混凝上成功的将钢梁的塑性铰逼离焊道,使钢梁在SRC柱混凝土面外形成良好的塑性铰。本研究之梁柱接头试体在反复载重作用下,可以发展出稳定且饱满的迟滞循环（Hysteretic Loop）。两组接头试体之钢梁塑性转角（Plastic Rotation Angle）达到5．4%和6．0%rad,梁柱接头之层间变位角（Interstory Drift Angle）达到6．2％与6．7％rad,显示此两组梁柱接头均具有优良的塑性变形能力,超过AISC Seismic Provisions（2002）所订4％rad层问变位角之要求。本研究依据有限的试验结果初步证实,在适当设计下,此种型式的梁柱接头将可以发挥良好的耐震性能。     

轻钢龙骨复合墙体节能设计方法与研究进展

轻钢龙骨结构体系作为一种节能、环保、施工效率高的结构形式,近年来在住宅建筑中运用日益广泛。但由于钢材的高导热性,钢龙骨处极易形成热桥,导致墙体内表面温度低,容易结露。在严寒地区应用这种结构墙体,热桥现象更为突出,同时还会对人体造成较强的冷辐射,使人体感觉不舒适。因此,深入研究轻钢龙骨复合墙体的节能设计方法,对于在严寒地区推广应用这种结构体系具有重要意义。详细介绍轻钢龙骨复合墙体的两种常用节能设计方法（外保温法和轻钢龙骨腹板开孔法）和两类外墙传热性能的分析方法（数值方法和物理试验研究法）,最后介绍轻钢龙骨复合墙体传热性能的研究进展。     

阀体与阀盖连接螺柱（螺纹）强度计算方法的探讨

分析了连接螺柱（螺纹）强度计算用公英制转换和压力级转换的条件不等式产生偏差的原因,论述了API600标准中不等式的K值在公称压力（PN）的DIN系列钢制阀门的计算中存在的问题,探讨了多项阀门国家标准引用的不等式中参数“PN”的定义、系数值和表达式,提出了筒化和统一计算方式的建议。