共查询到18条相似文献，搜索用时 343 毫秒
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半刚性连接钢框架有限元分析和研究 总被引：6，自引：1，他引：6
对带双腹板顶底角钢连接钢框架进行了非线性有限元分析，得到了钢框架的弯矩图以及应力梯度图等分析结果。同时进行了有限元分析结果与实验结果的对比，初步探讨了带双腹板顶底角钢连接对钢框架性能的影响。 相似文献
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运用有限元ANSYS软件和欧洲规范EUROCODE3给出的钢材在高温环境下的热物理及力学特性参数,建立了3个不同顶底角钢厚度的带双腹板顶底角钢梁柱连接的有限元分析模型。运用热-力耦合分析方法,对双腹板顶底角钢梁柱连接在高温下的抗火性能进行了深入研究,探讨了顶底角钢厚度变化对连接在高温环境下受力机理以及螺栓预紧力受温度影响的规律,所得结果对该类节点的抗火设计具有一定的参考价值。 相似文献
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框架竖向承重构件失效后,节点的性能决定了荷载是否能可靠地传递给相邻构件。栓焊刚性连接具有较高的初始刚度,在大变形条件下梁端母材易过早断裂,悬链线机制的发挥无法保证;顶底角钢腹板双角钢半刚性连接虽然具有较大变形能力,但在早期小变形阶段承载力偏低,性能有所不足。为全面提高节点的抗倒塌性能,设计了1种螺栓-组件连接节点,通过建立理论模型与数值模型进行相互验证,对该连接方式的抗倒塌性能进行了细致分析。结果表明:螺栓-组件连接子结构初始阶段承载力高于栓焊连接,并且在过渡阶段稳定上升,具有较大的转动变形能力。通过将梁腹板局部加厚,可使其在大变形条件下的承载力高于双腹板顶底角钢半刚性连接,抗倒塌性能优越。该新型连接节点传力明确,各组件工作性能合理高效,理论分析表明组件约束长度β、壁厚h和滑道长度d是影响其抗倒塌性能的关键因素,并给出了设计建议。 相似文献
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半刚性连接钢框架抗震性能的模型试验研究 总被引：3，自引：0，他引：3
通过两榀1／2比例的一跨两层半刚性连接钢框架模型的低周反复荷载试验，研究了框架模型的破坏机制、、出饺顺序、滞回特性、耗能能力等抗震性能。从而得出结论：具有腹板双角钢的顶底角钢连接的钢框架由于节点连接刚度较小，因此框架在侧向力作用下变形较大，但同时此连接也改善了梁柱的内力分布，提高了框架的耗能能力，增加了结构抗震性能。 相似文献
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初始连接刚度在节点刚度分类和钢结构地震分析中占有很重要的地位，因此研究连接的初始刚度很有现实意义。主要研究带双腹板顶底角钢连接初始刚度的确定方法以及影响其性能的主要因素。 相似文献
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腹板双角钢连接框架-非加劲薄钢板剪力墙抗震性能试验研究 总被引：1，自引：0，他引：1
对一榀1/3比例的单跨两层梁柱腹板双角钢连接框架-非加劲薄钢板剪力墙结构进行了水平低周往复加载试验研究.从承载力指标、刚度指标、延性指标、消能指标、破坏顺序和破坏模态以及连接节点的受力变形性能对试件作出评价,探究节点刚度与墙体的相互影响效果.结果表明:试件具有较高水平承载力和初始抗侧刚度,试件延性良好.结构具有理想的屈... 相似文献
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基于RC框架前期的水平低周反复荷载试验研究,采用有限元软件SAP2000对该试验试件进行了Pushover分析,模拟结果与试验值基本符合。以此为基础,通过定义材料的弹性模量即改变刚度,来表达RC框架的损伤程度,从而建立角钢加固损伤RC框架结构的有限元分析模型,继而对该模型进行了Pushover分析,研究角钢加固损伤RC框架结构的抗震性能及损伤程度对加固框架的影响。计算结果表明,角钢加固后RC框架的承载力大幅度提高,RC框架加固前的损伤降低了极限荷载,且大幅度降低了延性系数,说明损伤程度对加固后框架的延性耗能能力影响很大。 相似文献
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A refined probabilistic assessment of seismic demands and fracture capacity of welded column splice (WCS) connections in welded steel moment resisting frames (WSMRFs) is presented. Seismic demand assessment is performed through cloud-based nonlinear time history analysis (NLTHA) for two case-study structures, i.e., a 4- and a 20- story WSMRFs. Results from NLTHA are used to derive fracture fragility of WCS connections. To this aim, the study investigates (1) optimal ground-motion intensity measures for conditioning probabilistic seismic demand models in terms of global (i.e., maximum inter-story drift ratio) and local (i.e., peak tensile stress in the flange of WCSs) engineering demand parameters of WSMRFs; (2) the effect of ground-motion vertical components on the longitudinal flange stress of WCS connections and their resulting fracture fragility; and (3) the effect of WCS capacity uncertainties on the fracture fragility estimates of those connections. For the latter case, an advanced finite element fracture mechanics-based approach proposed by the authors is employed to capture aleatory and epistemic uncertainties affecting fracture capacities. The focus is on pre-Northridge WCS connections featuring partial joint penetration and brittle materials, making them highly vulnerable to seismic fracture. Fracture fragility results for the case-study structures are compared and discussed, highlighting the importance of the considered issues on fragility estimates, particularly in the case of high-rise structures. Findings from the study contribute shedding some light on the influence of seismic demand and capacity uncertainties on the assessment of fracture fragility of WCS connections. These findings can guide similar performance-based assessment exercises for WSMRFs to inform, for instance, the planning and design of retrofitting strategies for those vulnerable connections. 相似文献
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A new type of beam-to-column connection for steel moment flames, designated as a ＂self-centering connection,＂ is studied. In this connection, bolted top-and-seat angles, and post-tensioned （PT） high-strength steel strands running along the beam are used. The PT strands tie the beam flanges on the column flange to resist moment and provide self-centering force. After an earthquake, the connections have zero deformation, and can be restored to their original status by simply replacing the angles. Four full-scale connections were tested under cyclic loading. The strength, energy-dissipation capacity, hysteresis curve, as well as angles and PT strands behavior of the connections are investigated. A general FEM analysis program called ABAQUS 6.9 is adopted to model the four test specimens. The numerical and test results match very well. Both the test and analysis results suggest that： （1） the columns and beams remain elastic while the angles sustain plastic deformations for energy dissipation when the rotation of the beam related to the column equals 0.05 tad, （2） the energy dissipation capacity is enhanced when the thickness of the angle is increased, and （3） the number of PT strands has a significant influence on the behavior of the connections, whereas the distance between the strands is not as important to the performance of the connection. 相似文献
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Experimental study on seismic behavior of semi-rigid connection between steel beam and concrete wall
Beam-column or beam-wall connections are an important problem in high-rise buildings. In this study, based on the analysis of an example structure, an analytical model for design of the semi-rigid connections between steel beams and RC walls in high-rise hybrid buildings is proposed. Also, the mechanical characteristics of these connections subjected to lowreversed cyclic loading are investigated through comparison of experimental results from three semi-rigid connections and two rigid connections. Moreover, some latent problems for design of these connections as well as the corresponding solutions are discussed. The results from the experiments and analyses indicate that semi-rigid connections exhibit satisfactory capacity and seismic performance, and the proposed design can be used in practice. 相似文献
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On‐line hybrid test method for evaluating the performance of structural details to failure 
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下载免费PDF全文 A test environment to evaluate the seismic performance of gusset plate connections intended for steel braced frames is proposed. The developed test method combines the substructuring techniques with finite element analysis methods in an on‐line hybrid scheme. Numerical substructure analysis is conducted on bracing members, while bracing connections are treated as experimental substructures. A force‐displacement combined control imposed with the aid of 2 jacks ensures physical continuity between the analysis and test. The rotational behavior of gusset plate connections subjected to large inelasticity and varying axial loading until fracture is investigated. Two gusset plate details were designed and tested to verify the efficiency of the proposed method. The test method is rational, and smooth operation is achieved. The test results revealed the advantage of the developed on‐line hybrid test method in exploring the ultimate capacity of bracing connections. 相似文献
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Performance-based seismic design of integral abutment bridges 总被引：1，自引：1，他引：0
Integral abutment bridges (IAB) are experiencing increasing diffusion in the short to mid-range lengths, where they offer some advantages over traditional girder bridges with non-monolithic connection at the abutments. One challenging problem with their analysis and design is that consideration of the interaction between foundation soil, structure and backfill is unavoidable, also for the deck design. Further, the end of the construction is only one of the conditions that need to be verified during design. Cyclic deformations, such as those occurring during ground shaking, typically lead to an increase in stresses in the abutments and connections, due to progressive compaction (ratcheting) of the backfill soil. This problem is magnified when the bridge is comprised between two embankments, whose response may amplify the input motion and drive the deformation of the bridge. Performance-based design aims at superseding current design procedures by explicitly checking that the target performances set out are achieved, and not overly exceeded. Such a design paradigm naturally calls, on the one hand, for improved accuracy in response determination and more refined analyses, and, on the other, for taking into account the uncertainties entering into the problem by means of an explicitly probabilistic approach. With this objective in mind, the paper presents an inelastic dynamic model for the seismic analysis and design of IABs. The model, that features a balanced compromise between the setup and evaluation effort on one hand, and accuracy on the other, has been developed for implementation in typical commercial analysis packages. It builds on 1D site-response analysis and on inelastic Winkler-like modeling, to reproduce the main physical aspects of the seismic response of IABs. One example application to a highway overpass in Italy illustrates the model and the relevance of a fully probabilistic approach to performance-based design. The application offers also important insight into the choice of an efficient intensity measure for this type of structure. 相似文献
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The methodology for dealing with spatial variability of ground motion, site effects and soil–structure interaction phenomena in the context of inelastic dynamic analysis of bridge structures, and the associated analytical tools established and validated in a companion paper are used herein for a detailed parametric analysis, aiming to evaluate the importance of the above effects in seismic design. For a total of 20 bridge structures differing in terms of structural type (fundamental period, symmetry, regularity, abutment conditions, pier‐to‐deck connections), dimensions (span and overall length), and ground motion characteristics (earthquake frequency content and direction of excitation), the dynamic response corresponding to nine levels of increasing analysis complexity was calculated and compared with the ‘standard’ case of a fixed base, uniformly excited, elastic structure for which site effects were totally ignored. It is concluded that the dynamic response of RC bridges is indeed strongly affected by the coupling of the above phenomena that may adversely affect displacements and/or action effects under certain circumstances. Evidence is also presented that some bridge types are relatively more sensitive to the above phenomena, hence a more refined analysis approach should be considered in their case. Copyright @ 2003 John Wiley & Sons, Ltd. 相似文献