Based on the element of beam with hinges in OpenSees, the linear elastic shear restoring force model, defined on the level of section, was adopted. The zero length section element with bond-slip material was introduced to simulate the bond-slip at the end of element. Meanwhile, the geometric nonlinearity caused by P-D effect which is additional overturning moment resulted from the vertical load was taken into consideration. The Mohle-Kunnath constitutive model which is able to accurately simulate the low-cycle fatigue damage and cracking phenomenon of steel was used to analyse the mechanical properties of components under different loading histories. The mechanical properties of components were studied under monotonic loading, asymmetric cyclic loading and symmetric cyclic loading. Under different cycle number, the mechanical properties of components with symmetric and asymmetric loading and the characteristics of steel strain varied with displacement loading history were further analysed. The results indicate that under cyclic loading conditions, stiffness degradation and strength degradation phenomena on colums of reinforced concrete frame are obvious. The damage of components gradually exacerbates with the decrease of shear span ratio and the increase of shaft pressure ratio, while the damage is more clear with the increase of cycle number. The strain of reinforced materials varies significantly with the increase of cycle number. The stiffness degradation and strength degradation become more obvious with the increase of axial compression ratio and the decrease of shear span ratio, and the strain of steel also increases to some extent.%基于OpenSees中的BeamwithHingesElement单元,采用直接在截面层次上定义线弹性剪切恢复力模型,引入零长度单元利用粘结滑移材料模拟构件末端粘结滑移,考虑竖向载荷产生的附加倾覆力矩P-D效应引起的几何非线性,钢筋材料采用能精确模拟钢筋低周疲劳损伤与开裂现象的Mohle-Kunnath本构模型,分析构件在不同加载历史条件下的力学特性.研究构件在单调加载、非对称循环加载、对称循环加载条件下构件的力学特性,并进一步分析构件在不同循环周数条件下对称、非对称加载时构件的力学特性及钢筋材料应变随位移加载历史的变化特点,分析结果表明,钢筋混凝土框架柱在循环加载条件下的构件刚度退化、强度退化现象明显,构件的损伤程度随着剪跨比的降低和轴压比的增大逐渐加剧,构件随着循环周数的增加损伤程度更明显,钢筋材料应变随着循环周数的增加变化明显,随着轴压比增加和剪跨比的降低,构件刚度退化与强度退化随循环周数的增加更显著,钢筋应变同样有一定程度增加.
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