高强混凝土柱滞回性能数值分析

Numerical Analysis on Hysteresis Performances of High-strength RC Columns

目的通过在高强混凝土柱中配置强度超过1000 MPa的纵向和横向高强钢筋的方法,改善柱的滞回性能,以提高其抗震能力.方法为定量研究配有高强钢筋的高强混凝土柱的滞回性能,利用“条带法”,在平截面假定的条件下,编制了非线性分析程序,该程序考虑了钢筋和混凝土应力应变关系的全过程,P-Δ效应,核芯混凝土的约束强化作用,保护层剥落影响及塑性铰影响等因素;利用该程序进行了柱在低周反复荷载作用下的强度和变形分析,绘出了P-Δ滞回曲线;将计算的结果与试验结果进行了比较研究.结果数值分析和试验结果之间的差异在合理范围之内;轴压比对高强钢筋高强混凝土柱的滞回性能影响较大.结论利用所提出构造处理方法可以明显提高柱子的延性;采用数值分析的方法,可以计算出配有高强钢筋的高强混凝土柱子的延性,为抗震设计提供了一种便捷的方法.

The purposes of this paper are focused on increasing effectively the hysteresis performances of high-strength reinforced concrete members and structures. The seismic performances of flexural member can be improved by both confining sufficiently the core concrete and placing reasonably the longitudinal rebars, which the strengths of longitudinal and transverse reinforcement exceed 1000 MPa in the columns. Firstly, in order to develop numerically the numerical analysis method for the seismic properties of these kinds of columns, the ＂strip method＂ based on the plane hypothesis was used and a non-linear analysis computing software was edited which considered the whole-process stress-strain relationship of concrete and steel rebar, P-△ effects, confinement enhancing function of the core concrete, spalling of the cover, and plastic hinges etc;Additionally, the software was used to analyze the forces and deformations of the columns under the reversed cyclic loading, and the p-△ hysteresis curves were drawn; Finally, the comparing study between the experimental and theoretical results was carried out numerically. The results of study show that the differences between theoretical and testing data are relatively small and the compression force ratio greatly influenced the ductility of these columns. In addition, the ductility can be increased obviously by using the method mentioned in the paper which can provide an efficient numerical analysis method for the seismic design of the RC columns.