组合剪力墙的滞回性能研究

组合型钢剪力墙刚度大、延性好,在土木工程中应用广泛。组合型钢剪力墙一般通过铺设与钢板连接的混凝土层或纤维增强复合板形成。本试验和数值研究主要分析剪力钉间距、中间梁刚度、梁柱连接方法对组合型钢剪力墙性能的影响。结果表明:增大剪力钉间距可减小荷载-位移曲线的斜率,并提高结构韧性。中间梁刚度和梁柱连接对组合型钢剪力墙性能的影响是非常微小的,可以忽略。     

循环荷载下组合剪力墙的性能评估

组合钢板剪力墙(CSSW)由于其具有极高的刚度及可变性,在土木工程领域内应用广泛。它可以用于混凝土覆层,与钢板采用剪切螺钉连接,或者与FRP板黏结。现有的试验和数值研究集中在剪切螺钉间距变化时,梁跨中刚度和梁柱连接方法对组合钢板剪力墙的影响上。结果显示:剪切螺钉间距的增加使荷载-位移曲线斜率减小,改善了由特定螺钉间距影响的延性。此外,梁跨中刚度和梁柱节点对组合钢板剪力墙也有很显著的影响。     

组合剪力墙的滞回性能评价

组合型钢剪力墙刚度大、延性好,在土木工程中应用广泛。组合型钢剪力墙一般通过铺设与钢板连接的混凝土层或纤维增强复合板形成。本试验和数值研究主要分析剪力钉间距、中梁刚度、梁柱连接方法对组合型钢剪力墙性能的影响。结果表明:增大剪力钉间距可减小荷载-位移曲线的斜率,并提高结构韧性。中梁刚度和梁柱连接对组合型钢剪力墙性能的影响非常小,可以忽略。     

循环荷载下组合剪力墙的滞回性能评价

组合型钢剪力墙刚度大、延性好,在土木工程中应用广泛。组合型钢剪力墙一般通过铺设与钢板连接的混凝土层或纤维增强复合板形成。本试验和数值研究主要分析剪力钉间距、中间梁刚度、梁柱连接方法对组合型钢剪力墙性能的影响。结果表明:增大剪力钉间距可减小荷载-位移曲线的斜率,并提高结构韧性。中间梁刚度和梁柱连接对组合型钢剪力墙性能的影响是非常微小的,可以忽略。     

组合剪力墙的滞回性能评价

组合型钢剪力墙刚度大、延性好,在土木工程中应用广泛。组合型钢剪力墙一般通过铺设与钢板连接的混凝土层或纤维增强复合板形成。本试验和数值研究主要分析剪力钉间距、中梁刚度、梁柱连接方法对组合型钢剪力墙性能的影响。结果表明:增大剪力钉间距可减小荷载-位移曲线的斜率,并提高结构韧性。中梁刚度和梁柱连接对组合型钢剪力墙性能的影响是非常微小的,可以忽略。     

Experimental investigation of composite shear walls under shear loadings

One of the efficient methods for improving the seismic behaviour of high-rise buildings is using Composite Steel Plate Shear Wall (CSPSW). In this paper, extensive experimental studies of one and three-story CSPSWs with the scale of 1:3 and 1:4, together with stress equations of each element are reported. The experimental results indicate that this system has reliable behaviour if the columns have high bending stiffness. Also bolts spacing to plate thickness ratio has direct relationship with system ductility. However, plate yield load has an inverse relationship with this ratio. In this system, plate stiffening requirement is obtained with minimum reinforcement for reinforced concrete, though for damage prevention high strength concrete is preferred. Also, the results show a good agreement for the recommended values of (b/t) by an AISC code for preventing plate buckling.     

Push-out tests and a new approach for the design of secondary composite beam shear connections

Most of the design approaches currently used around the world take into account the weakening effect of trapezoidal types of steel decking in the vicinity of a shear connection by applying a reduction factor to the nominal strength that the same connection would have in a solid concrete slab. Numerous push-out test results on shear connections incorporating this type of decking are presented. These demonstrate that not every shear connection incorporating profiled steel decking which is within the limits of the associated standards, can be classified as sufficiently ductile. A new and more reliable design approach is proposed which also allows for the inclusion of special reinforcing devices to overcome these brittle behaviours. The key element of this design approach is to classify the anticipated connection behaviour, with respect to its deformation capacity, into either ductile or brittle, hence ensuring satisfactory shear connection behaviour where these types of trapezoidal steel decking are used.     

Headed steel stud anchors in composite structures, Part I: Shear

The formula in the 2005 American Institute of Steel Construction Specification to compute the strength of headed steel stud anchors (shear connectors) in composite steel/concrete structures has been used in the United States since 1993, after being proposed based primarily on the results of push-out tests. In the past several decades, the range of members used in composite structures has increased significantly, as has the number of tests in the literature on the monotonic and cyclic behavior of headed studs in composite construction. This paper reviews 391 monotonic and cyclic tests from the literature on experiments of headed stud anchors and proposes formulas for the limit states of steel failure and concrete failure of headed stud anchors subjected to shear force without the use of a metal deck. Detailing provisions to prevent premature pryout failure are also discussed. This paper also reviews proposals from several authors and provides recommended shear strength values for the seismic behavior of headed studs. The limit state formulas are proposed within the context of the 2005 AISC Specification, and comparisons are made to the provisions in the ACI 318-08 Building Code, the PCI Handbook, 6th Edition, and Eurocode 4. The scope of this research includes composite beam-columns [typically concrete-encased steel shapes (SRCs) or concrete-filled steel tubes (CFTs)], concrete-encased and concrete-filled beams, boundary elements of composite wall systems, composite connections, composite column base conditions, and related forms of composite construction.     

Headed steel stud anchors in composite structures, Part II: Tension and interaction

The 2005 AISC Specification for Structural Steel Buildings is the leading specification for composite construction in the US. However, these provisions do not provide a recommendation for computing the strength of headed steel stud anchors (traditionally used as shear connectors) under tension or combined tension and shear. Headed stud anchors are subjected to these types of forces in composite structures such as infill walls, composite coupling beams, the connection region of composite columns, or composite column bases. While the ACI 318-08 Building Code, the PCI Handbook, 6th edition, and CEB Design of Fastenings in Concrete include provisions for such conditions, those provisions are geared for more general anchorage conditions than are typically seen in composite construction. It would thus be beneficial to have design guidance specifically for the case of headed steel stud anchors subjected to tension or combined tension and shear in composite construction, evaluated within the context of the AISC and EC-4 Specifications. In this work, different strength equations to compute the nominal tensile strength of a headed stud are reviewed and compared to experimental results. The resulting recommendations seek to ensure a ductile failure in the steel shank instead of a brittle failure within the concrete. Several criteria are proposed to ensure that ductile failure controls in composite construction, and, different headed stud configurations and detailing reinforcement recommendations are proposed to improve the ductile behavior of headed stud anchors subjected to tension and combined tension and shear.     

Capacities of headed stud shear connectors in composite steel beams with precast hollowcore slabs

In steel-concrete composite beams, the longitudinal shear force is transferred across the steel flange/concrete slab interface by the mechanical action of the shear connectors. The ability of the shear connectors to transfer these longitudinal shear forces depends on their strength, and also on the resistance of the concrete slab against longitudinal cracking induced by the high concentration of shear force. Most of the research in composite construction has concentrated on the more traditional reinforced concrete and metal deck construction, and little information is given on shear capacity of the headed studs in precast hollowcore slabs. In this paper, a standard push test procedure for use with composite beams with precast hollowcore slabs is proposed. Seven exploratory push tests were carried out on headed studs in solid RC slabs to validate the testing procedures, and the results showed that the new test is compatible with the results specified in the codes of practice for solid RC slabs. Once a standard procedure is established, 72 full-scale push tests on headed studs in hollowcore slabs were performed to determine the capacities of the headed stud connectors in precast hollowcore slabs and the results of the experimental study are analysed and findings on the effect of all the parameters on connectors’ strength and ductility are presented. Newly proposed design equations for calculating the shear connectors’ capacity for this form of composite construction are also be given.     

Performance of shear connection in composite beams with profiled steel sheeting

This paper describes the structural performance of shear connection in composite beams with profiled steel sheeting. An accurate and efficient nonlinear finite element model was developed to study the behaviour of headed stud shear connectors welded through-deck. The profiled steel sheeting had transverse ribs perpendicular to the steel beam. The material nonlinearities of concrete, headed stud, profiled steel sheeting, reinforcement and steel beam were included in the finite element model. The capacity of shear connection, load-slip behaviour of the headed stud, and failure modes were predicted. The results obtained from the finite element analysis were verified against experimental results. An extensive parametric study was conducted to study the effects on the capacity and behaviour of shear connection by changing the profiled steel sheeting geometries, the diameter and height of the headed stud, as well as the strength of concrete. The capacities of shear connection obtained from the finite element analysis were compared with the design strengths calculated using the American Specification, British Standard and European Code for headed stud shear connectors in composite slabs with profiled steel sheeting perpendicular to the steel beam. It is found that the design rules specified in the American and British specifications overestimated the capacity of shear connection, but the design rules specified in the European Code were generally conservative.     

Experimental study of low-yield-point steel plate shear wall under in-plane load

This paper describes the study of the low-yield-point (LYP) steel plate shear walls under in-plane load. In the LYP steel plate shear wall system, LYP steel was selected for the steel plate wall while the boundary frame was constructed by the high strength structural steel. A series of experimental studies examined the inelastic shear buckling behavior of the LYP steel plate wall under monotonic in-plane load. The effects of width-to-thickness ratio on the shear buckling of LYP steel plates were examined. The stiffness, strength, deformation, and energy dissipation characteristics were investigated by performing cyclic loading tests on the multistorey LYP steel plate shear walls. Excellent deformation and energy dissipation capacity were obtained for all specimens tested. The LYP steel plate shear wall system is able to exceed 5% of storey drift angle under lateral force.     

Design and behavior of light composite steel-concrete trusses with drilled standoff screw shear connections

Composite steel-concrete flexural members have become increasingly popular in the design and construction of floor systems, structural frames, and bridges. A subtype of such composite floors is a system featuring composite trusses, also referred to as composite open-web joists, which can span large lengths and provide open web space for the installation of typical utility conduits. One problem that arises with respect to composite joists has been the installation of welded shear studs. In many composite trusses, the composite action can significantly reduce the required size and thickness of the top chord. The thinner the top chord member becomes, the more difficult it is to weld studs without burning through the base member. Likewise, as the joists get smaller, the greater the sweep (lateral out-of-straightness) tends to become. For these reasons, a form of shear connector other than welded shear studs is of interest. The results of the elemental push-out tests, analytical study and the resulting strength prediction models for the strength of the shear connection have previously been presented by the authors. This paper presents the analytical and experimental findings pertaining to the design and behavior of composite truss members with standoff screws as shear connectors.     

小径木组合墙骨剪力墙力学性能试验研究

提出一种机械连接小径木组合墙骨,并通过试验验证其用于轻型木框架剪力墙的可行性。进行了24片东北落叶松小径木组合墙骨剪力墙的抗侧性能试验,包括12片单调加载试验及12片低周往复加载试验,考查了小径木组合墙骨剪力墙的破坏模式、抗剪强度、割线刚度、极限位移、延性、抗力衰减系数等指标,并探究端墙骨及覆面板用材种类对墙体性能的影响。试验发现:小径木组合墙骨可部分替代规格材用于木骨架剪力墙中,并获得总体上相近的抗侧承载能力;端墙骨选用规格材或小径木组合墙骨所致整体性能差异较小;覆面板材料选取及布置方式对抗侧性能影响显著,双侧布置OSB板墙体承载力显著高于一侧布置石膏板、一侧布置OSB板墙体以及单侧布置OSB板墙体。     

装配式剪力墙齿槽式连接受剪性能研究

为研究装配式剪力墙齿槽式连接的受剪性能,进行了8片1/2缩尺剪跨比为0.54的齿槽式连接试件单调推覆加载试验。研究了装配式剪力墙齿槽式连接的破坏模式、开裂形态、荷载-位移曲线和承载力,分析了轴压比、暗柱设置、齿槽长度等因素对装配式剪力墙齿槽式连接受剪承载力的影响。结果表明：轴压比对齿槽式连接试件的开裂模式影响较大,轴压比较大的试件,裂缝开展以对角线方向的斜裂缝为主;轴压比较小的试件,裂缝开展以齿槽接合面裂缝为主;增加轴压比和设置暗柱提高了装配式剪力墙齿槽式连接的受剪承载力,齿槽长度对装配式剪力墙齿槽式连接受剪承载力影响较小。基于现有研究成果和试验结果,提出了装配式剪力墙齿槽式连接受剪承载力计算式,其计算结果与试验结果吻合较好。     

Non-linear model for stability of thin-walled composite beams with shear deformation

A geometrically non-linear theory for thin-walled composite beams is developed for both open and closed cross-sections and taking into account shear flexibility (bending and warping shear). This non-linear formulation is used for analyzing the static stability of beams made of composite materials subjected to concentrated end moments, concentrated forces, or uniformly distributed loads. Composite is assumed to be made of symmetric balanced laminates or especially orthotropic laminates. In order to solve the non-linear differential system, Ritz's method is first applied. Then, the resulting algebraic equilibrium equations are solved by means of an incremental Newton–Rapshon method. This paper investigates numerically the flexural–torsional and lateral buckling and post-buckling behavior of simply supported beams, pointing out the influence of shear–deformation for different laminate stacking sequence and the pre-buckling deflections effect on buckling loads. The numerical results show that the classical predictions of lateral buckling are conservative when the pre-buckling displacements are not negligible, and a non-linear buckling analysis may be required for reliable solutions.     

钢板-混凝土组合剪力墙受剪性能试验研究

通过11片高宽比为1.5、轴压比为0.5的钢板-混凝土组合剪力墙抗震性能试验研究,对比了不同连接形式钢板-混凝土组合墙受剪破坏形态、极限承载力及延性性能。试验表明,钢板-混凝土组合墙中型钢、钢板与混凝土可很好地协同工作,而且四周焊接的钢板-混凝土组合墙可大幅度提高受剪承载力,而延性与普通配筋墙相当或略高;采用连接板与周边型钢连接的钢板-混凝土组合墙,其承载力提高幅度取决于连接板的强度,延性性能较好。基于承载力叠加原理提出的钢板-混凝土组合剪力墙受剪承载力设计计算公式与试验结果吻合较好,并具有适当的安全度,同时还提出了钢板-混凝土组合剪力墙受剪截面控制条件的建议公式。     

框架剪力墙结构设计中的问题

针对高层建筑结构设计采用钢筋混凝土框架-剪力墙结构,介绍钢筋混凝土框架-剪力墙结构设计中的若干问题的处理方法,重点讨论剪力墙数量的确定及混凝土框架-剪力墙结构的地震反应分析。     

钢-混凝土组合梁在负弯矩作用下抗剪性能的试验研究

通过3根钢-混凝土组合梁在负弯矩作用下的试验,研究了其变形发展及破坏过程,得到了组合梁的跨中剪力-挠度曲线、交界面滑移曲线和沿截面高度分布的应变变化曲线,分析了剪切连接程度、截面尺寸、剪跨比、材料强度、钢筋配置等因素对组合梁承载力和延性的影响。对钢梁进行了塑性分析,得出在负弯矩作用下钢-混凝土组合梁抗剪承载力的提高不是由于钢梁腹板的硬化效应所致,而是由于混凝土翼板的贡献,并提出了考虑混凝土翼板影响的组合梁在负弯矩作用下抗剪承载力计算公式。将计算结果与实测结果进行了比较,二者吻合良好。     

LQ550高强冷弯薄壁型钢组合墙体受剪性能试验研究

为研究OSB板和水泥纤维板作为LQ550高强冷弯薄壁型钢组合墙体结构面板时的受力性能,进行7个不同结构面板的LQ550高强冷弯薄壁型钢组合墙体试件的水平单调加载和低周反复加载试验研究,分析了组合墙体的受剪承载力、延性系数、耗能系数等。结果表明：面板拼缝是组合墙体的薄弱部位;在水平接缝处设置宽而完整钢衬板的墙体试件具有较高的受剪承载力和抗侧刚度;单面水泥纤维板单调加载时比低周反复加载时承载力提高约8.79%~12.27%,其受剪承载力较低,但屈服前试件基本完好;对于双面板墙体试件,无论在单调加载还是反复加载时,其承载力、抗侧刚度约为各单面板试件相应指标之和。低周反复加载试件的耗能系数基本接近。