摘要
以钢框架中栓焊连接组合梁柱子结构(两跨三柱型)为研究对象,通过单调静力加载试验研究其在中柱失效工况下的破坏模式和力学机理。试验结果表明:靠近失效柱处梁端受拉翼缘首先断裂,裂缝不断向上发展直至腹板断裂。试件在大变形阶段因双跨组合梁之间的协同作用可提供高于前期受弯阶段的承载力。此外,建立了精细化有限元分析模型并与试验结果进行验证,在此基础上,探讨了周边构件的轴向约束对梁柱子结构的抗倒塌承载能力的影响,结果显示梁柱子结构的抗倒塌承载能力会随着周边构件提供的轴向约束增大而提升,但当超过临界值后,其对组合梁柱子结构的抗倒塌承载能力影响很小。通过足尺模型对比分析了带楼板和不带楼板试件的抗倒塌性能,结果表明考虑楼板组合效应试件较不带楼板试件,梁机制峰值承载力提高了42.0%,悬链线机制峰值承载力提高了49.9%。说明楼板组合效应可以显著提高结构在梁机制和悬链线机制的承载能力。最后基于能量平衡原理得到了结构的动力响应曲线,对比可知楼板的存在可使结构在动力荷载作用下表现出更为富余的抗倒塌能力储备。
To investigate the failure mode and mechanical mechanism of steel frames under middle column removal scenario,a composite beam-column substructure with bolt and weld rigid connections,being comprised of three columns and two beams,was selected as the research object to conduct monotonic static loading tests.The test results show that the tension flange at the beam end near the failure column fractures first,and the cracks continue to develop upward until the web fractures.The specimen can provide higher resistance in large deformation stage than in the previous bending stage due to the synergistic effect.In addition,a detailed finite element model was established and validated by test results.On this basis,the influence of the peripheral components′constraints on the anti-collapse performance of the assembly was assessed.The results show that the anti-collapse resistance of the beam-column substructure will be improved by the increase of peripheral components′constraints.When the constraints provided by peripheral components exceed the critical value,it will have only little effect on bearing capacity against progressive collapse.The anti-collapse resistance of specimens with and without floor slabs were analyzed by a full-scale model.The results show that the peak bearing capacity due to the flexural mechanism of the specimen with floor slabs is increased by 42.0%and that due to the catenary mechanism by 49.9%compared with the specimen without floor slabs.It shows that the composite effect of floor slabs can significantly improve the bearing capacity of the structure by both the flexural mechanism and catenary mechanism.The dynamic response curves of the structure were obtained based on the principle of energy balance.The comparison shows that the existence of floor can make the structure own relatively rich strength redundancy under dynamic load.
作者
钟炜辉
谭政
宋晓燕
孟宝
郑玉辉
ZHONG Weihui;TAN Zheng;SONG Xiaoyan;MENG Bao;ZHENG Yuhui(School of Civil Engineering,Xi’an University of Architecture and Technology,Xi’an 710055,China;Key Lab of Structural Engineering and Earthquake Resistance,Ministry of Education,Xi’an University of Architecture and Technology,Xi’an 710055,China)
出处
《振动与冲击》
EI
CSCD
北大核心
2021年第10期261-270,共10页
Journal of Vibration and Shock
基金
国家自然科学基金面上项目(51678476)
陕西省重点研发计划项目(2018ZDXM-SF-097)
陕西省教育厅重点科学研究计划(20JY033)
国家自然科学基金青年基金(51908449)。
关键词
组合梁柱子结构
静力试验
数值模拟
贡献系数
composite beam-column substructure
static test
numerical simulation
contribution coefficient
