短肢墙纵向应变分布演化过程研究

Experiments on non-flanged shallow-section shearwall structure about its strain distribution evolution process under horizontal cyclic loading

短肢墙是指肢长与厚度比值(肢厚比)在5～8之间的抗震墙,这种结构体系广泛应用于住宅工程。低周反复试验揭示了矩形截面短肢墙从弹性应力状态逐渐演化,直至破坏的全过程。通过试验结果与有限元分析的对比,给出了肢厚比为5,6.5和8三种情况下矩形截面试体应变演化全过程。结果表明:相对于弹性分析结果,短肢墙存在着明显的应力重分布;墙肢底截面纵筋应变基本符合平截面假定;当肢厚比为5时,墙肢底部纵筋首先屈服,肢厚比大于5时连梁箍筋首先屈服;连梁中部纵筋应变随肢厚比增加而增大。

shallow-section shearwall(SSSW) is defined as the shear wall with a ratio ranging from 5 to 8 of its section depth to width (RDW).The SSSW structure is widely used in residence projects in recent years.The horizontal cyclic loading tests on non-flanged SSSW specimens manifest the whole evolution process of strain distribution corresponding to each loading step,from elastic to plastic,until steel yielding.With RDW being 5,6.5 and 8,three specimens are discussed in detail about the comparison of finite element analysis results and the experiment results.There is large scale of strain redistribution since concrete cracking to steel yielding.The longitudinal strain distribution in the bottom section of limb is roughly consistent with Bernoulli's principle.With RDW being 5,the longitudinal bar in limb yields firstly,while the stirrup in linking-beam yields firstly when RDW greater than 5.The strain of longitudinal bar in the linking-beam increases with increscent of RDW.