混合联肢部分外包组合剪力墙基于两阶段耗能的塑性设计方法研究

TWO-STAGE ENERGY DISSIPATION-BASED PLASTIC DESIGN METHOD FOR THE HYBRID COUPLED PARTIALLY ENCASED COMPOSITE SHEAR WALL

混合联肢部分外包组合剪力墙结构是一种典型的两阶段耗能结构体系。依据现行设计规范设计的混合联肢部分外包组合剪力墙结构对结构弹塑性阶段的整体性能缺乏考虑,在设防地震和罕遇地震作用下结构的屈服顺序难以控制。基于混合联肢部分外包组合剪力墙结构体系“小震不坏,中震可修,大震不倒”的三水准抗震设防性能目标,提出结构两阶段耗能的塑性设计方法。以目标位移和理想破坏模式作为预测结构弹塑性受力状态性能目标,针对不同地震水准下的性能目标,考虑耦连比对结构合理耗能机制的影响,将结构的能力曲线等效为三线型,改进了传统基于能量平衡的塑性设计方法,保证结构在设防地震及罕遇地震下实现理想屈服顺序,避免薄弱层产生。采用建议的设计方法设计了一个12层结构算例,并采用ABAQUS对算例进行推覆分析和弹塑性时程分析。结果表明,采用基于两阶段耗能的塑性设计方法预测的中震及大震下结构顶点位移角与数值分析结果误差分别为0.5%和12.1%,最大层间位移角满足结构弹塑性层间位移角的要求。算例结构能够实现“强节点弱构件、强墙肢弱连梁”合理的屈服顺序,保证结构预期的失效机制和不同地震水准作用下的性能目标,验证了基于两阶段耗能的塑性设计方法的有效性。

The hybrid coupled partially encased composite shear-wall structure is a typical two-stage energy dissipation system.According to the current design code,the design of hybrid coupled partially encased composite shear wall has not considered the overall performance of the structure in the elastic-plastic stage.Under the action of fortification earthquake and rare earthquake,the yield sequence of the structure is difficult to control.Based on the three-level seismic fortification performance goal:“no damage in small earthquake,repairable in moderate earthquake,and no collapse in large earthquake”,a two-stage energy dissipation-based plastic design method is proposed.The target displacement and ideal failure mode are taken as the performance targets to predict the elastic-plastic stress state of the structure.According to the performance objectives under different earthquake levels,considering the influence of coupling ratio on the reasonable energy dissipation mechanism of the structure,the capacity curve of the structure is equivalent to three lines,and the traditional plastic design method based on energy balance is improved,so that the ideal yield sequence can be realized,and the weak layer can be avoided under fortification earthquake and rare earthquake.Upon the proposed design method,a 12-story structure is designed,and the static elastic-plastic time history analysis is carried out by ABAQUS.The results show that:the errors of the peak displacement angle predicted by the plastic design method based on two-stage energy dissipation is 0.5%and 12.1%,respectively,compared with the numerical analysis results under moderate and large earthquakes.The maximum inter-story displacement angle meets the requirements of elastic-plastic inter story displacement angle.The example structure can realize the reasonable yield sequence:“strong node weak member,strong wall limb weak coupling beam”,to ensure the expected failure mechanism of the structure and the performance goal under different seismic levels,thusly to verify the effectiveness of the plastic design method based on two-stage energy dissipation.