在以往12根1/2比例钢筋混凝土柱低周疲劳试验研究基础上,分析了不同位移幅值下弯曲型破坏混凝土柱的累积损伤发展规律,重点研究了钢筋混凝土柱的强度退化、刚度退化、能量耗散等力学性能。研究结果表明:钢筋混凝土柱的低周疲劳破坏过程一般可分为损伤迅速发展、相持及破坏3个阶段;强度退化和刚度退化与构件的损伤过程发展一致,导致其产生的根本原因是构件弹塑性性质及损伤的发展;构件破坏时滞回耗能随加载路径不同而存在显著差异,裂缝的开展和分布状态对构件耗能能力有明显的影响。
Based on existing low-cycle fatigue tests on 12 identical half-scale reinforced concrete columns,the development of cumulative damage of reinforced concrete frame column was investigated.Furthermore,the rigidity deterioration,strength deterioration and energy dissipation of reinforced concrete columns were studied.The results indicate that the failure process of reinforced concrete columns can be divided into three stages:damage rapid development stage,stalemate stage,and failure stage.The stiffness degradation traces and rigidity deterioration traces are accompanied with the failure process.The reason lies in the essential feature of elastic-plastic behavior of member and the development of damage.In addition,the energy dissipation is related to the loading path and is influenced by the crack development and crack distribution of column.