采用通用有限元法分析组合板的剪切机理

混凝土-冷弯异型钢组合板的强度取决于钢-混凝土界面的纵向剪切破坏。在目前设计过程中,通常采用的纵向剪切强度设计方法,如them-k法和部分交互法,均基于足尺试验,经济性差,耗时长,且仍是半经验的。建立组合板的通用有限元法,将钢-混凝土剪切面作为接触问题,考虑粘贴和摩擦。在分析模型中考虑几何非线性和材料非线性。进行推出试验,验证初步有限元分析,并考虑接触面的粘贴和摩擦。采用本接触模型对组合板的受弯性能进行有限元分析。通过对比组合板的推出试验和弯曲试验,对基于非线性接触理论的有限元分析进行验证。结果表明:基于界面接触模型的有限元分析与试验结果吻合较好,可用于分析组合板的性能和极限承载力。     

压型钢板-混凝土组合楼板的承载能力研究

压型钢板-混凝土组合楼板的承载能力受楼板叠合面的纵向抗剪能力控制。本文通过3组组合楼板的荷载试验,研究了单跨简支组合楼板和两跨连续组合楼板的极限抗剪和抗弯性能。试验结果表明:组合楼板的极限承载能力受叠合面的纵向抗剪能力控制;与简支组合楼板相比,连续组合楼板承载能力有明显提高,跨中挠度显著减小,端部支座剪力出现滑移时与简支板端部剪力值相近,显示了连续组合板的端部滑移与剪力的关系与简支板的情况相似。但与简支组合板不同的是,连续组合板端部出现滑移后,其极限承载能力明显高于相同跨度简支板极限承载力。根据试验结果,得到了组合楼板叠合面纵向抗剪能力的计算公式。在组合楼板的承载力设计中,应对支座端部的竖向剪力进行叠合面的纵向抗剪能力验算,文中提出了连续组合楼板的承载力计算方法。     

Inelastic behaviors of steel shear tab connections

Inelastic behaviors of shear tab connections commonly used in modern steel buildings are investigated in this work. Full‐scale steel shear tab connections with and without concrete slab physically tested by other researchers are closely simulated by non‐linear finite element (FE) method. Different nonlinear FE features (inelastic materials, surface‐based contacts and large geometric options) are included, and different solution strategies (Newton method and Explicit Dynamic method) are employed to balance computational effort and solution accuracy. The simulations extend our understandings on shear tab connections at micro levels, including stress distribution in the connection zone, movement of the neutral axis along the beam sections and normal stress distributions along steel shear tabs and concrete slabs. It is found that the shear tabs contribute to flexural strength of the beam‐to‐column connection and the elastic–plastic theory explains the observed behavior well only when concrete slab is not present. The composite steel shear tab connections have unsymmetrical behavior under negative and positive bending moments. The compressive concrete slabs significantly increase the flexural stiffness and strength of composite shear tab connections. It is also verified that the shear studs near steel columns play a key role for the composite connections. Copyright © 2013 John Wiley & Sons, Ltd.     

New evaluation and modeling procedure for horizontal shear bond in composite slabs

A new method for modeling the horizontal shear bond in steel deck-concrete composite slabs is proposed. The method considers the slab slenderness as the strength parameter that affects the accuracy of horizontal shear bond modeling. A calculation procedure called the Force Equilibrium method is developed to generate shear bond stress versus end slips relationship (shear bond property) from bending tests. An interpolation procedure is also presented to estimate the shear bond property curves for slabs of varying slenderness using two sets of bending test data. The shear bond property curves are applied to connector elements of finite element models to model the horizontal shear bond behavior in composite slabs. The results of this study show that the shear bond of composite slabs under bending varies with the slenderness parameter, and hence influences the slab strength and behavior, as well as affecting the accuracy of the finite element analyses. The finite element analyses conducted on slabs with different slenderness utilizing a single shear bond property, which are not varied according to the slenderness parameter, may lead to either safe or unsafe results, depending on the geometry of the slabs.     

Shear capacity of connect construction between corrugated steel web and concrete lower slab

为改善波形腹板与底板连接构造混凝土浇筑质量与耐久性能,提出翼缘钢板下移至混凝土板底面,开孔板连接件垂直焊接于波形钢板并贯穿钢筋的下包型连接构造。通过设计具有不同开孔板厚度、形状及焊接宽度等参数的连接构造试件,开展标准推出试验,研究其受剪承载力、抗剪刚度、剪切破坏模式以及相对滑移特征。在试验研究的基础上,考虑钢材理想弹塑性、混凝土塑性模型以及钢-混凝土界面非线性接触,建立适用连接构造受剪分析的精细有限元模型,分析结果与试验结果吻合较好。通过验证的有限元模型进行参数分析,结果表明,增加开孔钢板的厚度和混凝土的抗压强度可有效提高受剪承载力。最后,基于模型试验与有限元参数分析结果,提出布置开孔板连接的下包型构造受剪承载力的计算式,可对开孔钢板连接面外受剪承载力进行较为准确地预测。     

对组合钢梁-预制空心板中栓钉连接件的性能分析

在钢-混凝土组合梁中,剪切连接件的机械作用使得纵向剪力转移到钢翼缘/混凝土板的接合处。这种转移能力取决于剪切连接件的强度和混凝土板抵抗由剪力高度集中所导致的纵向开裂的能力。大多数对组合结构的分析都集中在传统的钢筋混凝土和金属面板结构,而对预制空心板中栓钉的剪切能力研究很少。本文对带栓钉的预制空心板组合梁结构提出标准的推力试验方法。一共进行7组测试性试验,试验结果显示新方法符合钢筋混凝土楼板规范要求。在确定这个新的标准方法后,对栓钉进行了72个足尺推力试验,确定了该类型连接件的性能,通过分析试验结果,还指出了各类参数对连接件强度和延性的作用。本文还提出了这种剪力连接件的设计公式。     

压型钢板-混凝土组合楼板纵向受剪承载力试验研究

针对组合楼板主要的破坏模式——纵向剪切破坏进行分析,对8块U76型压型钢板-混凝土组合楼板进行了静力试验。试验结果表明:组合板越厚、剪跨越小、剪力横向钢筋越多,组合板纵向受剪承载力就越高。通过与无栓钉组合板的试验结果比较分析,表明组合板中剪跨区的栓钉,能极大地提高受剪承载力;并通过试验得到组合板的荷载-纵向相对滑移关系曲线图,采用欧洲规范4的建议公式,以试验数据为依据,回归得出组合楼板的剪力粘结系数m、k,为该种楼板的工程设计提供参考依据。     

组合楼板横向剪切粘结分析及模拟方法

提出压型钢板-混凝土组合楼板横向剪切粘结性能的模拟方法,考虑影响模拟准确性的楼板长细比和强度参数。采用力平衡法推导出抗弯试验中剪切粘结应力与端部滑移量的关系(剪切粘结特性)。建立方程,利用2组抗弯试验数据,估计不同长细比下楼板的剪切粘结特性曲线。将该剪切粘结特性曲线应用于有限元模型中的连接单元,模拟组合楼板的横向剪切粘结性能。结果表明:组合楼板受弯下的剪切粘结性能随长细比变化,并影响楼板承载力、性能及有限元分析的准确性。采用不随长细比变化的剪切粘结特性对楼板进行有限元分析,分析结果并不可靠。     

压型钢板-混凝土组合楼板设计中的若干问题

针对钢 混凝土组合楼板叠合面的抗剪强度、连续组合板设计的纵向抗剪强度和剪跨以及端部锚固对板承载力的影响等问题进行了讨论和分析。在组合楼板的承载力设计中 ,应对支座端部的竖向剪力进行叠合面的纵向抗剪强度验算。对于连续组合楼板 ,可采用连续跨中正弯矩区的长度与简支楼板跨度等效的原则进行剪跨计算。端部锚固栓钉对组合楼板纵向抗剪强度的贡献可采用量化的公式进行计算     

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.     

带肋薄壁复式钢管混凝土柱的抗震性能研究

带肋薄壁复式钢管混凝土柱具有较好的耐火性能和经济性,同时钢管混凝土构件多用于地震频发区域,因此有必要研究其抗震性能。以轴压比和内管外径为主要参数,进行了6根带肋薄壁复式钢管混凝土压弯柱的低周反复加载试验。试验结果表明：该类组合柱的滞回曲线饱满,具有良好的抗震性能,其承载能力和耗能能力明显高于带肋薄壁钢管混凝土对比柱;该类柱均为面内压弯破坏;随着轴压比的增大,试件的延性、累积耗能随之减小,后期刚度退化加剧;随着内管外径的增大,试件的承载力、延性和耗能能力提高,但内管外径对刚度退化的影响较小。建立了带肋薄壁复式钢管混凝土柱的有限元模型,并利用试验结果检验了模型的准确性。基于该模型开展参数分析,结果表明钢管屈服强度、外部混凝土强度、轴压比、径宽比、径厚比和长细比等参数对该类构件的承载力影响较显著。最后基于参数分析,建议了荷载 挠度恢复力模型。     

钢-超高性能混凝土组合板冲切性能试验研究和承载力计算

钢-超高性能混凝土(UHPC)组合板是将钢板与UHPC通过连接件组合成整体,具有高强、高延性、抗开裂、施工便利等特性,可应用于桥面板、防护工程等结构中.由于钢-UHPC组合板相对较薄且往往承受集中荷载,因此需要对其抗冲切性能进行重点研究.通过变化连接件参数、UHPC厚度、钢板厚度和加载区边长,完成了14块板件在集中荷载...     

闭口型压型钢板——混凝土组合板承载能力试验研究

闭口型压型钢板—混凝土组合板中,压型钢板能更好地起到受拉钢筋的作用,比开口型压型钢板—混凝土组合板有更多性能优势和更好的应用前景。通过八块采用新型BONDEKⅡ型闭口型压型钢板的组合板的静力性能试验研究和理论分析,着重考察剪跨比和组合板端部栓钉布置对组合板受力性能、破坏形态和极限承载能力的影响,提出了该类闭口型压型钢板的组合板的受弯承载力、竖向受剪承载力和纵向剪切粘结破坏承载力的计算方法及公式,为组合板设计计算提供依据。     

钢混凝土组合桁架的纵向剪切力

钢混凝土组合桁架中钢和混凝土界面的纵向剪切分布一般是高度非均匀,在桁架节点出现峰值。对两个钢混凝土组合桁架梁的性能进行试验研究,所获试验结果对ANSYS软件包的非线性三维数值有限元模型进行校准。对30多个空腹板简支桁架中跨剪切变量进行研究,包括不同的荷载-滑移关系。在弹性阶段,尤其重要的是连接点受疲劳荷载导致塑性区的塑性重分配,使桁架节点连接处出现独特的剪切流峰值。数值结果与欧洲规范4进行比较,详细探讨了桁架节点剪切连接的增浓作用的影响。最后,对实际设计提出建议。     

钢板-混凝土组合板受弯性能试验研究

以钢板代替受力钢筋,通过栓钉将外侧钢板与内部混凝土板相连,二者共同作用形成钢板-混凝土组合板。根据钢板布置形式的不同,可将钢板-混凝土组合板分为单面钢板-混凝土组合板（SSC）和双面钢板-混凝土组合板（DSC）。通过对4个SSC试件和3个DSC试件的受弯试验研究,分析了不同钢板厚度、抗剪连接程度以及构造钢筋配置对组合板受弯性能和破坏形态的影响。试验结果表明,按完全抗剪连接设计的试件破坏形态与适筋梁相似,具有良好的受弯承载能力和延性;当受拉区钢板采用部分抗剪连接设计时,剪跨区栓钉易剪断导致承载力明显降低;当受压区钢板采用部分抗剪连接设计时,顶层钢板易发生局部屈曲,导致试件承载力和延性有所降低。基于试验结果,给出了钢板-混凝土组合板的受弯承载力计算式,计算值与试验值吻合较好。     

压型钢板组合楼板承载力的有限元分析

压型钢板组合楼板是 2 0世纪发展起来的一种新型结构形式。它具有显著的优势 ,如轻质、高强 ,施工快捷等 ,将在未来的建筑领域中大有作为。组合楼板的承载力主要取决于钢板 -混凝土界面处的抗剪强度。建立了一个二维有限元模型来研究单向组合板的性能。并将计算结果与试验数据进行对比 ,验证了模型的有效性     

考虑楼板组合作用的方钢管混凝土组合框架受力性能有限元分析

为了对组合框架结构的抗震性能进行深入的研究,基于方钢管混凝土组合框架低周往复荷载试验的足尺试件,采用通用有限元软件Msc.Marc建立了壳-实体精细非线性有限元分析模型,考虑了钢材及混凝土的弹塑性性能,混凝土的开裂及受拉软化,钢梁与混凝土楼板交界面的滑移以及钢梁下翼缘断裂等非线性因素,对4榀组合框架及2榀组合节点进行了...     

带肋冷弯薄壁方钢管混凝土柱滞回性能研究

对3根带肋冷弯薄壁方钢管混凝土柱进行滞回试验,主要参数为轴压比。试验结果表明：纵向加劲肋有效延缓了钢管壁局部屈曲的发生;其滞回曲线饱满,具有良好的耗能能力;随着轴压比的增大,柱承载力略有增大,而延性、耗能能力则明显减小;当横向位移大于6倍的屈服位移时,大轴压比的刚度退化速度最快。建立了该类试件的有限元模型,对比可得有限元模拟结果与试验结果吻合较好。基于有限元模型对该类构件开展机理分析和参数分析。结果表明：在带肋冷弯薄壁方钢管的约束下,核心混凝土的强度得到了较大提高;钢管局部屈曲发生在峰值荷载后,局部屈曲只发生在纵向加劲肋和钢管角部间;材料强度、轴压比、钢管宽厚比和长细比等参数对该类构件的承载力有较大影响;混凝土强度、轴压比和长细比对荷载-位移骨架曲线形状有较大影响。基于参数分析建议了该类构件的简化滞回模型,简化计算结果和有限元计算结果吻合较好。     

椭圆形钢管混凝土构件纯弯力学性能分析

利用有限元软件ABAQUS建立椭圆形钢管混凝土构件纯弯力学性能分析的有限元计算模型,并通过6个椭圆形钢管混凝土构件纯弯试验验证有限元计算模型的准确性。在此基础上对其受力全过程中钢管及混凝土应力分布情况进行分析,同时给出钢管与核心混凝土之间的相互作用,并对剪跨比、钢管强度、混凝土强度、短轴长和长轴长等参数对纯弯时构件极限承载力及荷载-位移曲线的影响进行比较。结果表明:椭圆形钢管混凝土构件在跨中发生倾向弯曲破坏,钢管屈服强度、混凝土强度、长轴长、短轴长及钢管壁厚等参数对其力学性能影响显著,剪跨比对其力学性能影响不明显。     

Experimental and numerical study on restrained composite slab during heating and cooling

In this paper, a series of fire tests on restrained composite slabs, carried out at the University of Manchester, is presented. A total of six composite slabs were tested under different fire scenarios, with different load ratios. The tests were particularly concerned with the variation of internal forces within the slabs during both heating and cooling phases. In addition to the testing programme, two separate nonlinear finite element models have been developed to simulate the thermal and mechanical behaviour of composite slabs during heating and cooling, which is introduced in detail in this paper. In the thermal analysis model, plane elements were adopted to obtain a detailed thermal behaviour. In the structural analysis model, the concrete, steel deck and mesh were simulated by solid elements, shell elements and truss elements respectively. The interaction between the concrete and steel sheet was simplified to spring elements. According to the experimental results and FE modelling, the behaviour of composite slabs was analysed in detail. At last, the parametric study was performed where the effect of concrete strength, steel deck thickness and mesh size was analysed.