外加强环不等高H型钢梁-方钢管柱节点抗震性能试验研究

通过对7个外加强环不等高H型钢梁-方钢管柱节点进行低周循环往复加载试验，研究节点域受剪承载力、滞回性能、变形能力和破坏模式。研究结果表明：试件的破坏形式有两种，分别为整体节点域的剪切破坏和局部节点域的剪切破坏；梁截面高度比和柱截面宽厚比是影响试件节点域承载力和剪切变形的主要因素；与此同时，随梁截面高度比和柱截面宽厚比的增加，节点域的耗能能力逐步增强；外加强环几何构造对节点域承载力和剪切变形也有一定影响，在框架柱端部弯矩增大系数较低的情况下，外加强环几何尺寸的增加对节点耗能能力有提高作用；节点域进入塑性阶段之前，各试件节点域的承载力无明显退化，从屈服到最终破坏，节点域承载力出现显著退化，承载力退化系数在0.89~0.96之间。不等高梁外加强环节点具有较好的变形能力和耗能能力，所有试件处于极限状态时的等效黏滞阻尼系数均在0.30～0.58之间。

Experimental investigation on seismic behavior of unequal-depthH-shaped steel beam to square steel column connectionwith external-diaphragm#br#

Cyclic loading tests of seven unequal-depth H-shaped steel beam to square steel column joint specimens with external-diaphragm were conducted to research the shear capacities, hysteretic performance, deformability, and failure modes of the joint panel zone. It is found that: all the specimens form two failure modes, including the shear failure of the entire panel zone and the shear failure of partial panel zone. Beam depth ratio and width to thickness ratio of steel column have great impacts on the shear bearing capacity and shear deformation of the entire panel. In addition, with the increase of beam depth ratio and width to thickness ratio of steel column, the energy dissipation capacity of the entire panel increases gradually. Dimensions of external-diaphragm have influence on the shear bearing capacity and shear deformation of the entire panel. On the condition of the small moment amplification factor of frame column, the larger size external-diaphragm can improve the energy dissipation capacity of the entire panel zone. Before the entire panel enters into plastic stage, the degradation of shear capacity of entire panel doesn’t occur. From the yield stage to failure, the shear bearing capacity degrades obviously. The shear capacity degradation factor ranges from 0.89 to 0.96. Unequal-depth-beam to column connections with external-diaphragm have good deformability and stable energy dissipation capacity. The equivalent viscous damping coefficients of panel zone range from 0.30 to 0.58 when the specimens are at the ultimate state.