圆钢管混凝土柱－H 钢梁内隔板式节点抗连续倒塌机理研究

摘要

To investigate the progressive collapse resistance mechanism for H-beam—concrete-filled steel tubular (CFST)column connections with inner-diaphragmjoints,a finite element model(FEM)for two half-span joint under the middle-column removal condition was established using ABAQUS.The displacement control loading method was used in FE andysis.The resistance capacity curves,failure modes and resistance mechanism curves of joints were calculated.The parametric analysis of H-beam—CFST column connections with inner-diaphragmjoints was conducted to find influence laws of different parameters,such as,beam strength,tube strength,core concrete strength,inner-diaphragm strength,steel ratio of column,thickness and width of inner-diaphragm,and span-depth ratio on joints'anti-collape capacity.The results indicated that the joints’failure evolution modes develop from beam flexural stage to catenary stage and damaged stage ultimately;increasing beam strength and decreasing span-depth ratio can obviously improve joints'resistant collapse capacity,increasing inner-diaphragm strength,width and thickness can reduce their resistant collapse capacity,and other parameters have no obvious influences.%为研究圆钢管混凝土柱－H 钢梁内隔板式节点抗连续倒塌工作机理，以中柱失效工况下的节点作为研究对象，采用 ABAQUS 建立了双半跨单柱型梁柱节点模型，在节点柱顶端进行位移加载，得到了节点的承载力曲线、破坏形态以及抗力机制曲线等，在此基础上对影响组合节点抗倒塌承载力的8个关键性参数进行分析，包括钢梁强度、钢管强度、混凝土强度、内隔板强度、柱含钢率、内隔板厚度、内隔板宽度以及跨高比。结果表明，内隔板式节点破坏是从梁机制阶段到悬链线机制阶段再到破坏阶段的发展过程；对节点参数分析可知增大钢梁强度和减小跨高比可显著的提高节点倒塌抗力，增大内隔板的强度、宽度和厚度节点倒塌抗力略有降低，其它参数影响不明显。