型钢混凝土T形柱-钢筋混凝土板新型节点冲切性能研究

Analysis on punching shear behavior of an innovative connection between T-shaped steel reinforced concrete column and reinforced concrete slab

为研究型钢混凝土(SRC)T形柱-钢筋混凝土(RC)板节点冲切性能,对3个T形SRC柱-RC板节点和2个方形SRC柱-RC板节点进行了竖向荷载作用下的冲切破坏试验。试验变量包括板厚、柱截面形状和有无柱帽。试验结果表明,所有试件耗能能力较弱,均发生了脆性冲切破坏。柱截面形状的变化会导致冲切剪应力的分布更为复杂,出现应力集中现象。增加板厚和设置柱帽可以有效提高板柱节点的冲切承载力和残余承载力。此外,采用ABAQUS软件进行了数值模拟分析。数值计算结果和试验结果在荷载-位移响应、混凝土应变和破坏模式方面具有良好的一致性。参数分析结果表明,柱内型钢能发挥对板内钢筋的悬挂作用,改善板柱节点的残余承载力。但配钢率的增加对残余承载力的提升并不明显。T形柱的肢高肢厚比对节点冲切承载力的影响可以忽略,增大柱帽的平面尺寸与截面高度均能够提高节点冲切承载力,相比之下柱帽截面高度对于冲切承载力的影响更为明显。

To study the punching performance of reinforced concrete(RC)slab-T-shaped steel reinforced concrete(SRC)column connection,the punching failure tests were carried out on three RC slab-T-shaped SRC column connections and two RC slab-square SRC column connections under vertical loads.The investigated test variables include slab thickness,cross-sectional shape of column and column cap.The test results show that all the specimens have weak energy dissipation capacity and are characterized by britle punching failure.The change of column cross-sectional shape may lead to more complex distribution of punching shear stress and stress concentration.Increasing slab thickness and setting column cap can effectively improve the punching bearing capacity and residual bearing capacity of the slabcolumn connections.In addition,the ABAQUS software is used for numerical simulation analysis.The numerical results and experimental results have a good agreement in load-displacement curves,concrete strain and failure mode.The parameter analysis results show that the steel in the column can resist and improve the residual bearing capacity of the slab-column connections.The increase of steel ratio,however,does not significantly increase the residual bearing capacity.The effect of the limb height-to-thickness ratio of the T-shaped column on the punching bearing capacity of the connection can be ignored.The punching shear capacity of the connection increases with the increase of the plane size and height of the column cap,but the effect of the height of the column cap on the punching shear capacity is more obvious.