为了研究带开孔损伤方钢管混凝土柱的破坏机理,设计了9个试件进行轴心受压试验研究,主要考虑开孔损伤率、混凝土强度等级、长细比3个变化参数,通过试验观察了试件的受力全过程及破坏形态,获取带开孔损伤方钢管混凝土柱的破坏机制、荷载.位移以及荷载-应变全过程曲线,并对其进行极限承载力的理论分析。研究结果表明,带开孔损伤方钢管混凝土柱的破坏形态表现为开孔处钢管撕裂和试件局部鼓曲破坏;混凝土强度等级对试件的荷载.位移曲线的形状影响不明显,但随着混凝土强度的提高,试件的承载力有较大的提升;试件表现出良好的延性,小开孔损伤时(体积开孔损伤率〈0.7%、截面开口损伤率〈2.5%),对方钢管混凝土柱的承载能力和变形性能影响较小。最后提出了带开孔损伤方钢管混凝土柱的极限承载力计算方法,研究结果可为相关学科的科学研究和工程应用提供参考。
In order to research the failure mechanism of concrete-filled square steel tubular columns with opening hole damage under axial compression loading, 9 specimens were studied. Three vary parameters such as opening hole damage rate, concrete strength grade and slenderness ratio were considered. In experiments, the whole process of stress and failure pattern was observed. The failure mechanism of concrete-filled square steel tubular columns with opening hole damage and the complete curves of load-displacement and stress-strain were obtained, and theoretical analysis of the ultimate bearing capacity was carried out. The results show that the failure pattern of concrete-filled square steel tubular columns with opening hole damage is tearing damage of steel tube in the opening bole area and local drum bow damage. Effects of concrete strength grade on load-displacement curve of specimens are not obvious. With the increase of concrete strengtb, beating capacity of specimens obviously increases. Specimens with opening hole damage still show good ductility. On condition of the small opening hole damage (volume opening hole damage rate 〈 O. 7% and section damage rate .〈 2.5% ) , influence on the beating capacity and deformation of concrete-filled steel tubular columns is small. Finally the ultimate bearing capacity calculation method of concrete-filled square steel tubular columns with opening hole damage was put forward. The research conclusions can provide reference for scientific researches and engineering applications.