方钢管混凝土柱-H形钢梁不同构造隔板贯通节点力学性能研究

为研究具有不同连接形式、隔板厚度和外伸长度的隔板贯通节点的力学性能,使用ABAQUS对不同构造节点进行数值模拟研究。基于试验结果验证了建模方法的准确性,并分别建立了全焊接、腹板栓接-翼缘焊接、下栓上焊、全螺栓四种连接形式的隔板贯通节点模型,对比了不同连接形式节点的力学性能,对产生差异的原因进行了机理分析。并进一步针对下栓上焊连接形式节点的隔板厚度、外伸长度对力学性能的影响进行了参数化分析。研究发现,具有翼缘螺栓连接形式的节点承载力更高且塑性铰远离节点核心区,基于此且考虑到施工因素,认为下栓上焊的连接形式具有显著优势;隔板过薄或隔板外伸长度过长均会降低该种节点的承载力和延性,隔板也会发生明显变形导致在核心区形成塑性铰,劣化节点受力性能。推荐工程中采用的隔板厚度宜比钢梁翼缘厚度厚3mm左右,隔板外伸长度宜控制在50~75mm。

Research on the Mechanical Behavior of a Diaphragm-through Connection Between Rectangular CFST Column and H-shaped Steel Beam with Different Structural Configuration

In order to study the mechanical properties of a diaphragm-through connection with different connection types,diaphragm thickness and extension length,ABAQUS was used to simulate and analyze the connections with different structural configuration.The accuracy of the model was verified through comparing with experimental results.Four types of connections were established,including fully welded,web bolted-flange welded,bottom flange bolted-top flange welded and fully bolted forms.The mechanical properties of connections with different types were evaluated and compared.The influence of thickness and extension length of diaphragm on the mechanical behavior of bottom flange bolted-top flange welded type connections was analyzed.It is found that the connections with bolted flange have higher bearing capacity and the plastic hinge is far from the core of connections.Combing with construction consideration,this study proves that the bottom flange bolted-top flange welded type has prominent advantages.Too thin diaphragm or too long extension length of diaphragm can reduce the bearing capacity and ductility of connections.The diaphragm which is thin or long can also have obvious deformation and generate plastic hinges in the core area,and thus degrades the mechanical behavior.It is recommended that the thickness of diaphragm should be about 3mm greater than that of steel beam flange,and the extension length should be controlled within 50-75mm.