The Elastoplastic Time History Analysis Of Complex Steel Structure With Taking The Dali Healthcare Buddhist Hall As Example

With the development of national economy, considering the superiority of green environmental protection, high strength, easy of standardization processing and site installation, steel structures was widely used in public buildings, which the structures have a complex function and a highly request of the safety, such as complex structures, large-space structures and high rise buildings. The object of this thesis is a high-rise and irregular steel structure, which located in the area with8degrees (0.30g) seismic fortification and nestled among hills, which has a comparatively uncommon structure irregularity and complexity. Therefore, the study of the anti-seismic property of the building has an important meaning for much theories and the engineering fulfillment.The main works of this paper are as follows:(1) The study of the steel structure elastoplastic analysis in domestic and abroad was reviewed in this paper.(2) Based on the existing transforming software "Midas2ANSYS.exe", a user interfaces of transforming the MIDAS/Gen model to ANSYS model was designed in this paper. The APDL commands were made with the Excel VBA, and almost thirty thousand command lines have been written in order to apply the loads, take analysis and get the results in this paper. In this way, the workload reduced and the error prevented.(3) The complex ANSYS model with using the BEAM188, SHELL181and the REINF265to simulate the model’s beams, columns, the concrete slabs and the reinforcements were finished in this paper.(4) The seismic response spectrum and time history analysis were taken in the MIDAS/Gen with99seismic waves.15seismic waves were selected with the analysis results which satisfied the demand of the code. With the time restrictions, the mode analysis and the elastoplastic dynamic time history analysis with only3seismic waves (2crude seismic wave and1artificial wave) in ANSYS were carried out in this paper.The main results of the thesis are as follows:(1) In recent years, the research mainly focuses on two aspects:①Some new theories and method were advanced based on the conventional theories.②Seeking the optimization of engineering with taking the elastoplastic analysis in the special projects.(2) The optimization and the secondary development are taken with the existing transforming software "Midas2ANSYS.exe", a user interfaces of transforming the MIDAS/Gen model to ANSYS model with the Excel VBA and APDL programming language is designed in this paper. The workload is reduced with this method and the meshing size can be controlled.(3) The results of the analysis in the frequent and infrequent seismic analysis shows that:①The seismic waves which produced the maximum structure response in the elastic time history analysis and the elastoplastic time history analysis are not the same.②The maximum node acceleration at the top is larger than the input peak acceleration about3-5or2times in the elastic and elastoplastic analysis respectively; so the cornice is about5.8or3.6times respectively.③When taking the elastoplastic analysis, the structure’s beams are under the bending moment, the horizontal shear force and the torque, even it connected to the floor, and the local plastic deformations on the slab were occurred where connected to the position of opening, this shows that the rigid-floor hypothesis should not be adopted in elastoplastic analysis.(4) The results indicate that:①The short column should be avoided in the designing of steel structure.②The column base reaction force in the infrequent earthquake is about2-3times larger than the frequent earthquake, and the column bottom nodes which connected to the support will bear more than20,000kN pulling force, therefore, the vertical compressive bearing capacity, the shear bearing capacity and the uplift bearing capacity should be fully considered in the large diameter manual hole digging pile designing of the rock foundation.③Several vertical components with smaller line stiffness will show local vibration phenomenon in the low-order, and the12floor of the structure is the weakest position among the building. Therefore, the security reserves of these kinds of components should be increased.