高强钢T形圆管相贯节点轴向滞回性能试验研究

Experimental Research on Hysteretic Behavior of High-Strength Steel CHS T-Joints Under Axial Loads

为研究高强钢T形圆钢管相贯节点的轴向滞回性能,对5个不同支管与主管截面外径比的高强钢T形圆管节点进行了支管轴向往复加载试验研究及有限元分析。从节点的破坏模式、滞回曲线、骨架曲线、耗能和延性等方面展开了分析,重点考察了节点几何参数的影响。试验结果表明:在支管轴向往复荷载的作用下,节点破坏模式为支主管相贯线处冠部附近主管壁开裂且裂缝沿主管横截面扩展,这与普通强度钢材T形圆管相贯节点的破坏模式有所不相同;各节点的滞回曲线均呈饱满的梭形,表明高强钢T形圆管相贯节点具有良好的抗震性能。分析研究表明:主管截面尺寸相同的试件的滞回曲线外形接近,主管截面尺寸是影响这类节点滞回性能的主要因素之一;有限元建模计算得到的节点破坏模式、滞回曲线和骨架曲线均与试验结果吻合良好,所建立的有限元模型能较好地模拟高强钢T形圆管相贯节点轴向滞回性能。

In order to study the hysteretic behavior of high strength steel circular hollow section(CHS)Tjoints under axial loads,five high-strength steel CHS T-joints under brace axial reciprocating loads with different outer diameter ratios of brace to chord were investigated experimentally and numerically.The hysteretic curves,skeleton curves,energy consumption,ductility and failure modes were analyzed,focusing on the effects of geometric parameters.The results showed that the failure mode of the joints under brace axial reciprocating loads was that the chord wall cracked near the crown area at the intersection line of braces and chords before the cracks expanded along the main pipe cross section,which was different from that of joints made of ordinary strength steel.The hysteretic curve of each joint was full shuttle shape which reflected good seismic performance for the high-strength steel CHS T-joints.The research also showed that the specimens with the same chord section expressed similar shape of the hysteretic curve,and the chord section was one of the main factors affecting the hysteretic behavior of this type of joints.The failure modes,hysteretic curves and skeleton curves of the joints calculated by finite element analysis were in good agreement with the test results,the finite element models established in the paper could well simulate the axial hysteretic behavior of high-strength steel CHS T-joints.