基于有限单元柔度法的钢筋混凝土空间框架非弹性地震反应分析

Flexibility based finite element method for inelastic seismic response analysis of reinforced concrete space frames

本文基于有限单元柔度法纤维模型梁柱单元理论,编制了钢筋混凝土空间杆系结构非弹性动力分析程序。通过对一个退台六层钢筋混凝土空间框架振动台试验结果与数值模拟分析结果的对比,对基于非线性有限单元理论和纤维模型的空间杆系分析模型进行钢筋混凝土空间框架非弹性地震反应分析的有效性进行了验证和评价。对地震振动台试验的模拟分析表明,纤维模型梁柱单元对中等以下损伤的结构地震反应具有很好的模拟能力,对于结构处于严重损伤的阶段,模拟所得的结构位移和损伤程度将会小于结构的实际位移和损伤程度,这可能是由于目前纤维模型梁柱单元尚不能考虑钢筋的粘结滑移以及将现浇楼板简单处理为刚性并未考虑楼板刚度实际会出现明显降低的现象所致。

Based on the analytical model for the beam column element using the finite element flexibility method and fiber model, a program was developed for inelastic seismic response analysis of reinforced concrete space frames. Its accuracy was verified by comparison of the shaking table experimental results of a six story reinforced concrete setback frame to the computed results. The simulation analysis results of the earthquake shake table test showed that the fiber model beam column element had well enough simulation ability to earthquake response of the low middle damage structures. As to structures existing in severe damage stage,simulative structural displacements and extent of the damage would be less than actual structural displacements and extent of damage. These may be caused by the fact that the fiber model beam column element coded presently does not account for the bond slippage of reinforced bars and cast in site floor slabs are treated simply as rigidity, whereas the rigidity will degrade apparently in course of the test.