Study On Seismic Damage Assessment Of Short Leg Shear Wall Structure

Short leg shear wall structure is a new type of structural system between shear wall and special-shaped columns, and it has been increasingly developed in high-rise buildings, especially high-rise residential buildings. However, this architecture has not been tested in rare earthquake, and people know little about the injury and damage of the structure. Also there is no corresponding provisions in the specification. At present, seismic energy damage analysis research about short leg shear wall structure is poor. The research on seismic damage assessment of short leg shear wall based on energy principle has impor tant theoretical significance. Therefore, researches have been done and the main contents are presented as follows:Firstly, the basic principle and method of the static elasto-plastic analysis and dynamic elastic-plastic analysis are introduced. The central difference method and Newmark- ? method in the dynamic elasto-plastic analysis are mainly introduced. And the seismic wave input by the elasto-plastic time history analysis is chosen.Based on general finite element software ABAQUS, the finite element model of the short leg shear wall is established. Through the modal analysis and the seven degree earthquake action The reliableness of the model is determined by the calculation results between ABAQUS and SATWE. The elasto-plastic time history analysis of the structure under rare earthquake was carried out. The calculating results, including basal shear time history curves, floor displacement angle envelope curves and vertex displacement time history curves were attained. It shows that the short leg shear wall structure has good mechanical performance and the structure can remain stable under rare earthquake. The damage location of the structure can be seen intuitively through the damage image, which provides a basis for the future seismic design.On the basis of the relative displacement energy equation, the comparative analysis of energy response under different seismic waves and the energy response of the structure under different seismic amplitudes are carried out. And the plastic damage energy of the corresponding structure can be obtained. It shows that the plastic damage state can be characterized by the plastic damage energy account for the proportion of the total input energy under earthquake load.Finally, based on the plastic damage model, the damage of the structure under the "resonance" excitation is studied. The damage state of the first two modes is obtained, which is the basic failure form of the structure, and the plastic damage energy of the corresponding basic failure mode is obtained, which is the ultimate bearing capacity of the first two modes. Based on the wavelet analysis principle, the input seismic wave is decomposed by wavelet transform. The seismic wave is decomposed into the wavelet band with the structure of the natural vibration frequency as the center. The wavelet band seismic demand energy is calculate, and as the seismic effect of each mode. Earthquake damage is a combination of various modes. O n the basis of wavelet analysis, a considering higher modes damage and can reflect the structural residual bearing capacity of short leg shear wall structure seismic damage assessment model is proposed based on the principle of energy. The damage state was classified scientifically. The overall damage index of structural damage is put forward, which can reflect the nature of the damage and the residual bearing capacity of the structure.