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

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.