The Seismic Response Analysis Of Large Chassis And Twin Towers Structure Under The Different Damping Models

With the development of Chinese economy and the progress of urbanization, people’s requirements of the building’s security and newness are becoming increasing, so, some kinds of irregular structure have been built, and the lager chassis and twin towers structure which belongs to them has been used widely. The technology of vibration and energy dissipation brace which are the main seismic control technology have been increasingly used in irregular structures. Study the vibration isolation performance of the large chassis and twin towers structure and its damping effect combined with energy dissipation brace, which is main point of the paper.Four kinds of analysis models of the larger chassis and two towers structure have been built. The model of the traditional seismic structure is the model 1; The model of the inter- layer seismic isolated structure is the model 2, on the basis of model 1, isolation layer was placed on the top of the larger chassis structure; The model 3 and model 4 are the combined structure of vibration isolation and energy dissipation brace, on the basis of model 2, model 3’s energy dissipation brace was placed in 1~3 floors, model 4’s energy dissipation brace was placed in 4~6 floors. Then, the model analysis and the linear time history analysis have been done in four kinds of models. The main point of the model analysis is to get the self vibration period and the natural frequency, the main point of the time history is to get the inter-layer displacement and the inter-layer shear force. The study mainly did some relative research as following:1.Did the model analysis for the models, and analysis the damping effect of model 2、3、4 through structure’s natural vibration period. The results show that: compared with model 1, model 2’s natural vibration period ware increased; compared with model 2, model 3、4’s natural vibration period ware not increased. According to structure’s natural vibration period, isolation layer can increase the structure’s natural vibration period, far from the site predominant period and major energy carrier frequency, so it has perfect damping effect. But the energy dissipation brace only can increase the structure’s damping, it is useless to structure ’s natural vibration period.2.Did the linear time history analysis for the str ucture, and analysis the damping effect through the contrast of model 1 and model 2. The isolation layer can reduce the structure’s inter-layer displacement and inter- layer shear force, it can increase the damping efficiency of the structure. But, the reliability of the isolation bearing must be ensured, and some necessary measures should be adapted to reduce the rising of the inter- layer shear force of isolation structure ’s large chassis under the rare earthquake.3.Did the linear time history analysis for the structure, and analysis the damping effect of energy dissipation brace through the contrast of model 2 and model 3. On the basis of isolation structure, the compared structure of isolation layer and energy dissipation brace can further increase the structure’s damping efficiency, but the increase is limited.4.Did the linear time history analysis for the structure, and analysis the damping effect of energy dissipation brace under the different places vertically through the contrast of model 2 and model 3. When the horizontal layout mode and the number are identical, on the basis of isolation technology, the damping efficiency of the energy dissipation which are placed in larger chassis is better than the damping efficiency of the energy dissipation whic h are placed in towers. Comprehensive consideration, model 4’s damping effect is the best, in this combined structure of isolation and energy dissipation, energy dissipation braces are arranged at the towers.