地震作用下框架-复合墙结构弹塑性内力计算

框架-复合墙结构是以框架和密肋复合剪力墙共同承担水平地震作用的新型组合式双重抗侧力体系,合理计算弹塑性阶段框架与复合墙的内力是决定大震下结构体系安全性能的关键问题之一.根据6榀典型密肋复合墙试验数据,建立了复合墙体指数式刚度退化模型,量化了墙体在各变形阶段的刚度退化系数.在对比复合墙与框架、混凝土墙、砌体墙刚度退化规律的基础上,分析了复合墙刚度退化对结构受力性能的影响,提出了弹塑性阶段框架-复合墙结构地震内力的实用计算方法,并通过具体算例讨论了结构内力的变化情况.研究结果表明：弹塑性阶段,框架与密肋复合墙刚度退化速度比值呈非线性关系,框架分担总地震剪力的比例增加,但其绝对剪力值增加幅度并不明显;考虑弹塑性阶段复合墙的刚度退化,更好地符合了地震下框架-复合墙结构的实际受力情况.

Elastic-Plastic Force Calculation of Frame-Composite Wall Structure Under Earthquake

Frame-composite wall structure is a new type structure system that consists of frames and composite walls to undertake horizontal earthquake action together. As to the safety performance of the structure system, it is one of key problems to calculate seismic forces of frame and composite wall rea- sonably. Based on 6 pin typical multi-ribbed composite walls test data, stiffness degradation model of composite wall is established, and stiffness degradation coefficients at different stages are quantified. From the comparison results among composite wall, frame, RC wall and masonry wall, and consider- ing the stiffness degradation of composite wall, the influence effects to bearing performance of structure are analysized, and then the practical computational method of earthquake shearing force on frame-composite wall structure is put forward. The influence degree is discussed with the concrete example. The results show that stiffness degradation velocity ratio between frame and composite wall exhibits nonlinear relation, and the shear-sharing ratio of frame increases, while the increasing extent of shear absolute value is not obvious. Stiffness degradation of the composite walls in elastic-plastic stages is taken into account, and it accords with the actual situation on frame-composite wall structure under earthquake action.