自攻螺钉、拉铆钉连接的受力蒙皮抗剪性能试验研究

本文对111个自攻螺钉、拉铆钉连接及14块由这种连接件连接的蒙皮板进行了抗剪性能试验,并分析了其抗剪强度、抗剪刚度、工作特点、破坏模式以及变更连接件布置方式、压型板跨度对受力蒙皮性能的影响。试验结果与国外的试验和理论分析结果符合较好。文中还提出了将压型钢板等效为正交各向异性板,用有限元法分析蒙皮的抗剪性能,所得蒙皮连接件内力分布规律,有助于进一步研究建立我国的蒙皮设计计算方法。     

建筑结构轻钢屋面板抗震试验和加固

对9个轻钢屋面板试件进行试验研究,以评估其抗震性能。根据当前的隔板设计方法,隔板能够提高承受动力荷载的剪切强度,而不是剪切刚度。此外,随着振幅增大,剪切刚度降低。使用较厚的面板或面板的安装方向与荷载方向平行时,隔板延性将降低。大多数损坏的隔板维修后可达到其初始强度,抗震加固措施能够有效增加电弧点焊/按钮冲隔板的剪切强度和刚度。     

Seismic response of building structures with flexible inelastic diaphragm

The inelastic response of one-storey buildings subjected to lateral loads is analysed, making allowance for the real in-plane rigidity and strength of the floors. The structural model consists of a floor diaphragm supported by seven vertical resisting elements with degrading stiffness properties. The elastic design analysis is carried out by modelling the floor diaphragm as a rigid or, alternatively, as a flexible beam. The actual nonlinear response of 240 structures is studied via numerical simulations. Different stiffness and strength distributions in the lateral resisting systems and in the diaphragm are considered. The results of the investigation emphasize the need for an adequate design of the floor diaphragm as a structural element. Also, the results show that the deformability of the diaphragms plays an important role only if the lateral-force resisting system has a markedly non-uniform stiffness distribution; even in such cases, however, adopting the rigid diaphragm hypothesis leads to a more conservative design.     

Collapse of stiffened box-girder diaphragms

The results of two large-scale tests on stiffened load bearing box-girder diaphragms which were designed to collapse in different modes are described in detail. A comparison is made between the experimental behaviour up to collapse and that predicted by a recently developed large-deflection elasto-plastic finite element analysis. It is shown that it is now possible to predict accurately the complex interaction between stiffeners and plate panels in such a diaphragm. Attention is drawn to the important effect the stiffness of the flanges and webs of the box has on the overall response and ultimate load of the diaphragm. It is concluded that the powerful computer programs which are now available have been validated by test results and provide suitable bases on which sound design rules may be formulated. Comments on the new British design rules for diaphragms are made in the light of the results of this study.     

Bemessungsvorschlag für Holz/Beton‐Verbundbalken unter Beachtung abgestufter Verbindungsmittelabstände

Design proposal for timber/concrete composite beams with graded connnector distances. The distance of connections of timber/concrete composite beams is often graded for economical reasons according the shear force distribution. The load‐carrying capacity of composite beams according to DIN 1052 respectively E DIN 1052 with internal forces, which are linearly determined, (γ‐procedure) are clearly reduced compared to beams without graded distances of connectors. The actual load‐bearing behaviour distinctly shows non‐linearities. The influence of the gradations of the connectors on the load‐bearing behaviour of composite beams is investigated, because the influence of the stiffness of connections on the load‐bearing capacity of composite beams is small. The paper presents a comparison between failure loads determined by FE‐analysis and the working loads according to the current design rule. It is shown that the decrease of load‐bearing capacity is smaller than assumed by current code of practice. Structures with several different distances of connections have the largest safety‐factor. These systems can more economically be designed. As the result of the investigations, a new design proposal is presented, which takes non‐linearities into account and guarantees a constant safety‐zone between failure load and working load. These proposal permits an economic design of timber/concrete composite beams.     

自攻螺钉连接的蒙皮组合体抗剪性能的试验研究(上)

受力蒙皮结构是一种新型的空间受力结构,受力蒙皮组合体是其重要的组成元件。为研究自攻螺钉连接的受力蒙皮组合体在平面抗剪性能,本文采用了卧式悬臂梁试验方案,进行了大小尺寸试件的对比试验,通过试验和总结前人成果的基础上,提出了非对称受力模型的概念,并据此给出了蒙皮组合体在平面强度和刚度简化计算公式。它与试验结果吻合较好。     

新型完全剪切连接钢筋混凝土组合扁梁受力性能试验

对一种新型钢筋混凝土组合扁梁一U形外包钢钢筋混凝土组合扁梁的受力性能进行了试验,共完成5根不同剪力连接形式的简支梁静荷试验,其中2根为部分剪力连接试件,3根为完全剪力连接试件.研究了不同的抗剪连接形式对组合扁梁整体工作性能和受力性能等方面的影响,对该组合扁梁的抗弯刚度和承载力进行了理论分析.结果表明,该组合扁梁具有良好的力学性能,在完全剪切连接情况下,该组合扁梁的截面应变近似符合平截面假定,抗弯刚度和承载力的计算可以忽略外包钢和其内部混凝土之间滑移效应的影响,其理论计算值与试验结果吻合良好.     

Theoretical investigations on load‐bearing capacity of RC flat‐plate framed structures subject to middle column loss

This paper presents theoretical studies on load‐bearing capacity of reinforced concrete flat‐plate framed structures. The existing methods for determining load‐bearing capacity of simply supported slabs are first reviewed, and their limitations are presented. An energy‐based refined method is then proposed to enhance the accuracy of the existing methods by considering the contributions to internal energy dissipation due to the extension of reinforcing bars along yield lines, the additional resultant bending moment from membrane forces, and the sectional bending moment along yield lines of slabs. The refined method for simply supported slabs is extended for fixed supported slabs, and thus, the load‐bearing capacity of reinforced concrete flat‐plate structures subject to a middle column loss is analytically determined. The performance of the proposed method is validated against test results and also verified against finite element analyses. Parametric studies are conducted to investigate the effect of reinforcement ratio, slab thickness and aspect ratio on the stiffness, and yield‐line resistance of structures. It is found that for the fixed supported slabs, it is reasonable to assume negative yield lines along the slab edges to consider the effect of obvious concrete crushing along the edge. Square slabs have higher ultimate loads than rectangular slabs, due to a longer horizontal yield line in the middle in the rectangular slab, which has detrimental effect on the sectional ultimate bending moment. The numerical results show that the reinforcement ratio has little effect on the initial bending stiffness and yield‐line resistance of slabs for a given slab thickness and aspect ratio. The initial stiffness and yield‐line resistance increase as the slab thickness increases. For the same reinforcement ratio and slab thickness, a larger aspect ratio leads to a lower initial bending stiffness, yield‐line resistance, and stiffness in tensile membrane action stage, due to a longer yield line along which tensile membrane forces have a detrimental effect on the sectional bending moment.     

一边固支三边简支预制矩形肋底板混凝土双向叠合板的简化弹性计算方法

结合预制矩形肋底板混凝土双向叠合板(简称双向叠合板)的受力特点,分析了当前实际工程设计中存在的问题。针对双向叠合板的正交构造异性特征影响,采用荷载叠加法和正交构造异性板理论求解了均布荷载下一边固支三边简支双向叠合板挠度及弯矩的解。通过对解作形式变换和引入等效跨度比,将双向叠合板等效为各向同性双向板进行计算,提出了简化弹性计算方法。编程计算得到了双向叠合板强、弱方向刚度比为0.5和2.0,以及等效跨度比在0.5~1.0时的弹性系数。介绍了按照等效跨度比查找各向同性双向板弹性系数的线性插值法,并与编程计算结果进行对比。结果表明:采用简化弹性计算方法得到的结果与编程计算结果吻合良好,完全能够满足工程设计要求,该方法准确可行。     

Influence of nonstructural components on roof diaphragm stiffness and fundamental periods of single-storey steel buildings

The stiffening effect of nonstructural roofing components on the in-plane shear stiffness of metal roof deck diaphragms was studied. Tests were performed to determine the properties of the non-structural roofing materials and the typical diaphragm connectors. A linear elastic FE model was used to establish stiffness values for common diaphragm configurations, and the results were applied to evaluate the impact of nonstructural roofing elements on the fundamental period of vibration of single-storey steel buildings. The shear stiffness increase due to the nonstructural components was found to be more pronounced for the flexible steel deck diaphragms. The influence on the period of vibration was negligible for most of the buildings studied.     

全装配式RC楼盖平面内受力性能试验研究

为研究全预制装配式钢筋混凝土楼盖的平面内受力性能,对1/2缩尺的楼盖模型进行了楼盖平面内拟静力试验,对楼盖的裂缝分布、破坏形态、平面内变形特征、滞回曲线、位移延性、刚度退化和耗能能力等进行了研究,分析了楼盖模型各连接件在加载过程中的板缝剪力和轴力分布规律。结果表明：新型楼盖具有较大的平面内刚度和较好的整体性能,在加载过程中梁 板连接件和板缝连接件均表现出良好的传力性能;新型楼盖具有一定的延性,但耗能能力不理想,说明基于弹性楼盖的抗震设计方法是必要的;加载初期楼盖的变形呈弯曲型,加载中后期随着楼盖损伤的积累,板缝间相对位移增大,变形模式逐渐向剪切型发展;新型楼盖在平面内荷载作用下内力分布规律与简支梁相近,研究成果可为新型楼盖平面内受力性能的理论分析提供参考。     

考虑剪切效应的钢筋混凝土厚板的纵向裂缝研究

试验表明,钢筋混凝土简支厚板在中置集中荷载作用下的双向弯曲很明显.特别是当板的宽跨比较大、集中荷载的面积较小时,其双向作用更为明显.按常规设计,往往只计算Mx方向配筋,而My方向则按构造配筋.因此,工程上经常出现沿板跨度方向的裂缝,即板的纵缝,并且由于My方向配筋过少,板纵向裂缝的宽度远大于横向裂缝的宽度.本文首先对简支厚板在集中荷载下的裂缝形态进行了试验研究,然后,将厚壳单元引入板的有限元分析,进而讨论了钢筋混凝土双向厚板的剪跨比、厚宽比、宽跨比对板横纵向弯矩比值的影响,提出了适用于控制不同厚度的厚板纵缝的纵向弯矩比简化计算公式,为设计提供参考.     

空间钢构架混凝土简支深梁静力性能试验研究和设计建议

为研究空间钢构架混凝土简支深梁的静力性能,进行了4根空间钢构架混凝土深梁试件和作为对比试件的2根普通钢筋混凝土深梁在竖向对称集中荷载作用下的模型静载试验。试验参数为跨高比、配筋方式等。试验结果表明,与相同条件（除配筋方式外）的普通钢筋混凝土深梁相比,配置空间钢构架的混凝土深梁不仅刚度增大,而且其受剪承载力和变形能力也有较大幅度的提高,合理配置空间钢构架可改善混凝土深梁的延性。除配置水平和竖向分布钢筋外,沿主拉应力迹线方向配置斜向分布钢筋,或沿主压应力迹线方向设置斜向暗梁等措施可进一步提高空间钢构架混凝土深梁的受剪承载力。结合试验结果及其分析,给出了空间钢构架混凝土深梁的设计建议和构造要求,包括深梁内空间钢构架的配置范围、材料要求、混凝土保护层厚度、承重空间钢构架设计方法以及深梁内斜向分布钢筋、斜向暗梁的构造要求等。图13表4参10     

夹芯墙板覆面冷弯薄壁型钢承重复合墙体受剪试验

为满足多层冷弯薄壁型钢房屋建筑的抗震及防火要求,同时兼顾施工便捷性,提出了夹心墙板覆面的新型冷弯薄壁型钢复合墙体,并完成了11片足尺模型水平加载试验。试验表明： 1） 复合墙体的受剪破坏主要由墙板周边的螺钉连接失效引起,即螺钉将墙板撕裂或螺钉剪断引起,墙板与自攻螺钉之间的连接力学性能成为影响复合墙体受剪性能的主要因素;增大墙板厚度或者采用玻镁板代替石膏板可提高复合墙体抗剪性能,而龙骨立柱的截面尺寸对复合墙体受剪性能影响不明显; 2） 同侧墙板层数的增加对复合墙体受剪承载力及刚度虽有明显提高,但未达到线性叠加程度;夹心墙板的使用有利于墙体蒙皮效应的发挥,相应的墙体受剪性能优于墙体同侧双层墙板覆面时的受剪性能; 3） 蒸压加气混凝土（ALC）板周边与自攻螺钉的连接区域在较低水平荷载作用下出现板材开裂现象,故不宜采取ALC板参与墙体受力的连接方式。研究给出了新型冷弯薄壁型钢复合墙体的受剪承载力及抗剪刚度设计指标,供工程设计参考。     

Laterally supported sandwich panels subjected to large deflections—Part 1: Test apparatus design and experimental results

This paper deals with the experimental characterization of the structural behavior of sandwich panels under distributed transverse loadings. A configuration typically used in aircraft interior applications is considered: a simply supported rectangular plate fixed by bolts on the two longitudinal edges or on all four edges. The panel and joint stiffness are experimentally evaluated and a test apparatus is designed and instrumented to measure the reaction shear loads at the panel attachment bolts and the transverse deflection of the plate. The results demonstrate the importance of a nonlinear analysis for the design of this type of structure. A companion paper, describes the FE analysis procedure utilized to simulate the nonlinear behavior of the tested panels. The numerical results are validated against the experimental results.     

自攻螺丝连接受力蒙皮体抗剪性能试验研究

受力蒙皮是考虑房屋屋面、墙面的压型钢板与框架、檩条进行可靠连接而共同工作的结构体系。本文对国内常用的V-840型压型钢板采用自攻螺丝连接的受力蒙皮体进行了抗剪试验研究,分析了不同间距自攻螺丝连接的受力蒙皮体的破坏形式及抗剪性能,并提出了不同间距布置的连接件对蒙皮体抗剪性能的影响,以及此类蒙皮体考虑蒙皮效应的条件。     

Die erdstatische Berechnung geotechnischer Flächentragwerke

Analysis of geotechnical plane structures. A geotechnical plane structure is an uniform loaded bearing layer that spans between point supports or line supports. The load transfer is based on the effect of vaults within the bearing layer and possibly the bearing capacity of an elastic diaphragm which may also be installed. First formulas are derived that allow the structural analysis of vaults and diaphragms. Using these formulas new solutions for the analysis of geotechnical plane structures are found. These solutions take into account the complex interaction between support pressure, the self weight of the soil and the limit state of the soil‐vault. The split of load between diaphragm and subsoil reaction is calculated stiffness dependent.     

Zur Traglastermittlung von Druckstäben im Holzbau

Determination of ultimate loads for compression members in timber constructions. The design of compression members in timber constructions has to consider the increasing stress due to the non‐linear behaviour of the members. The determination of the ultimate load of compression members requires the consideration of non‐linear geometric behaviour, if the bending moments increase more than 10% in relation to the linear theory. In the German timber design code, DIN 1052 [1], two methods of calculation are suggested. The second method uses geometric non – linear theory (theory second order) for calculation of the ultimate load. According to DIN 1052 the load carrying capacity can be determined without reducing stiffness parameters using the modification factor. The calculation methods for compression members according to DIN 1052 are compared and differences between them are discussed. A calculation with identical results for the ultimate loads using either the first or the second method is proposed.     

Optimum Design of Load-Bearing Box Girder Diaphragms having a central support

A parametric study is carried out to determine the optimum design of load-bearing box girder diaphragms which are supported on a single bearing positioned at the diaphragm centre line. The parameters varied include the depth/breadth ratio, the depth/thickness ratio, the size and location of stiffeners and the eccentricity of loading. The criterion used for comparison purposes is the collapse load for each configuration, this being determined using a finite element package. Finally, the effects on the collapse load of the different configurations are discussed and recommendations made.     

Seismic behavior of connections composed of CFSSTCs and steel-concrete composite beams — finite element analysis

Based on the experimental results of connections composed of concrete-filled square steel tubular columns (CFSSTCs) and steel-concrete composite beams with interior diaphragms, exterior diaphragms, or anchored studs, 3-D nonlinear finite element models were established to analyze the mechanical properties of these three types of connection using ANSYS. Finite element analyses were conducted under both monotonic loading and cyclic loading. The load-displacement and shear force-deformation curves of the finite element analyses are in agreement with those of the tests in terms of strength and unloading stiffness. Parametric analyses were conducted on the connections with exterior diaphragms under monotonic loading to investigate the influences of axial load ratio, width to thickness ratio, and dimensions of exterior diaphragms on the connection behavior. It was found that the strength and stiffness are less influenced by the axial load ratio and the dimensions of the exterior diaphragms, but more influenced by the width to thickness ratio of the steel tube under shear failure mode.