联肢剪力墙体系由于连梁的存在使得其在地震作用下的非线性行为与实体剪力墙结构相比变得更为复杂。该文改进了基于修正力插值单元(MFBFE)的柔度矩阵,将其作为该体系墙肢和连梁的非线性分析单元;建议了一种对角斜筋配筋方式连梁截面的剪切滞回模型(DCBHShear),其骨架曲线采用三折线型,包括开裂点、屈服点、极限点公式的确定,卸载、再加载刚度的变化通过剪切位移延性和刚度折减系数控制,捏拢影响由捏拢系数控制。在OpenSees中的单元类和单轴材料类开发改进的MFBFE单元和DCBShear模型,并结合实体剪力墙截面的剪切滞回模型(SWShear)和OpenSees中已有的单轴材料Steel02、Concrete02分别对两个四层1∶3缩尺的联肢剪力墙试件建模和非线性分析,给出了OpenSees框架下改进后的MFBFE单元调用这些单轴材料的实现方式。分析结果与试验结果对比显示该方法成功预测了两个试件的初始刚度、峰值力以及滞回耗能,具有较高的精度。
Coupled wall systems, compared with shear walls without openings, have more complex nonlinear behavior due to the existence of coupling beams. The Modified Force-Based Fiber Element(MFBFE), whose flexibility matrix is improved, is served as the nonlinear analysis elements of both wall piers and coupling beams. A hysteretic shear model(DCBHShear) for diagonal reinforced coupling beams was proposed. The envelope curve based on tri-linear model included the cracking, yielding and ultimate points. Changes of both unloading and reloading branches were governed by shear deformation ductility and stiffness reduction factor. Pinching coefficient controlled the effect of pinching. The codes of MFBFE and proposed DCBHShear, as well as another hysteretic shear model(SWShear) for shear wall without opening and the uniaxial materials named Steel02 and Concrete02, have been implemented in OpenSees to simulate two four-story specimens of coupled walls constructed at approximately a one-third scale. Analytical results including initial stiffness, maximum shear force and energy dissipation compared to corresponding experimental findings show a good level of agreement.