摘要
基于多层多跨平面钢框架在中柱失效工况下的有限元分析,提出了两跨三柱梁柱子结构的模型。以栓焊节点为例,采用ANSYS对三种子结构模型在中柱失效工况下的破坏过程和失效机理进行精细化有限元分析。结果表明,三种模型在不同程度上放大了节点的变形或钢梁的悬链线效应;提出的两跨三柱梁柱子结构模型能有效反映框架结构在连续倒塌工况下失效柱所在节点的边界条件。采用所提出的两跨三柱梁柱子结构模型,对传统栓焊(WUFB)节点、盖板加强型(WCPF)节点和翼缘削弱型(RBS)节点进行精细化有限元分析。结果表明,盖板加强型节点和翼缘削弱型节点能够实现塑性铰外移,抗连续倒塌性能优于传统栓焊节点;三种节点的抗倒塌性能对比关系与常用的半跨梁柱子结构模型的分析结果一致。
A two-span beam-to-column assembly model was proposed based on finite element(FE) analysis of a multi-story multi-span plane steel frame under bottom column remove scenario. Taking welded unreinforced-flange web bolted(WUFB) connection as an example, detailed FE models were established by ANSYS. Pushdown analyses were performed to analyze the failure process and mechanism characteristics of three beam-to-column assemblies under the middle column remove scenario. The results show that the three beam-column assemblies magnify the deformation of the connections or the catenary effect of the beams to a certain degree, and that the proposed beam-to-column assembly model can reflect the boundary conditions effectively of the beam and column in steel frames under progressive collapse scenario. Pushdown analyses of WUFB connection, web cover plated flange(WCPF) connection and reduced beam section(RBS) connection using the proposed assembly model were performed. The results show that WCPF and RBS connections realize the relocation of the plastic hinge and perform better than WUFB connection in progressive collapse scenario. The progressive collapse performances between these three connections are consistent with the FE analysis result using half-span beam-to-column assembly model.
引文
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