L形柱在反复荷载作用下的非线性分析

Nonlinear Analysis of L-Shaped Column Subjected Cyclic Loads

在平截面假定的前提下,将钢筋混凝土L形柱划分为两端弹塑性区、中间为弹性区的三分段杆单元模型。将应用于平面剪力墙的多垂直杆单元模型拓展为空间的多垂直杆单元模型,推导了拓展的多垂直杆单元模型单元刚度矩阵,经静力凝聚为三分段杆单元模型刚度矩阵,该单元模型可用于各种截面形式的钢筋混凝土异形柱、剪力墙墙肢和梁的非线性分析,计算工作量较小。讨论了目前垂直杆的轴向拉压滞回模型,提出了轴向拉压滞回曲线考虑骨架曲线下降段的简化处理方法。最后提供了算例,结果表明本文方法计算的滞回轴线与在反复加载下L形柱的试验结果吻合较好。

On the hypothesis of plane cross section, L-shaped reinforced concrete column was divided into three fragment line element of elasto-plastic zone at both ends and elastic zone in the middle. The multivertical line element model used to analyze plane wall structure was expanded to spatial one, which stiffness matrix was-derived. The three fragment line element stiffness matrix was drawn by static coagulation. This space element model could be suitable for special shaped coulumns, wall limbs and beams with all kinds of section form, and the nonlinear analysis workload is small. On the based of taking axial tension compression hysteresis of vertical line element, the simplified method of axial tension compression hysteretic curve considering the subsidence of skeleton curve was introduced. Finally, the examples show that the calculated hysteretic curve are good coincident with the test results of L-shaped column subjected cyclic loads.