考虑剪切滞后效应的钢筋混凝土剪力墙单元模型及应用

Element model of RC shear wall considering shear-lag effect and its application

多垂直杆单元模型是在钢筋混凝土剪力墙非线性分析中较为常用的一种宏观模型。现有的分析方法不能考虑翼板剪滞效应的影响,然而翼板上正应力非均匀分布必然影响剪力墙承载力的充分发挥。其次现有的分析方法大多不能较好地考虑垂直杆中正应力对剪切刚度的影响。本文在多垂直杆单元模型的基础上进行改进,把垂直杆的轴向刚度和剪切刚度相结合,并引入剪滞位移自由度,摒弃平截面假定的限制,对一工程结构模型的静力分析显示其变形状态符合受力机理,对3片短肢剪力墙模型和1片剪力墙模型进行弹塑性静力加载分析,计算结果与试验结果吻合较好,表明该方法应用可行。

Multi-vertical truss element model is the most widely used macroscopic model in nonlinear analysis of RC shear wall. Methods available can not consider the shear-lag effect, however, the non-uniform distribution of norreal stress in flange plate inevitably affects the full play of bearing capacity. The effect of normal stress in vertical truss on shear stiffness is mostly not considered in the methods available too. The multi-vertical truss element modelis improved by the combination of axial stiffness with shear stiffness in vertical truss and introducing the cross section displacement function, which considers the shear-lag effect in flange plate, thus it is free from the restriction ofplane section assumption. Static analysis of one engineering structure model shows the deformation state accords with mechanical mechanism. Three short-leg shear wall models and one shear wall model are respectively calculated byusing the static elastic-plastic simulative analysis, and the calculation results are consistent with the experimental results. It is proved that the method is feasible.