The Research Of The Elasticoplasticity On Point-supported Grid Frame And The Application Of Energy Dissipation Elements

In recent years, damping control technology has been widely studied and applied at home and abroad, and compared with the conventional anti-seismic methods, the use of viscoelastic dampers for vibration control has obvious technical advantages. Engineering practice shows that the rational use of damping control technology can effectively improve and enhance the anti-seismic performance of the structure. Currently, the damping control technology is mainly used in multi-level architectural structures, and there is a little research and application in large span architectural structures. In recent years, with the development of large span architectural structures, the increase of the span and the reduction of the supports will increase the stress of local members and made the members into the elastic-plastic state and become the incentive of structure damage, especially in areas with high anti-seismic fortification intensity, it have an important engineering application value on the elasticoplasticity and anti-seismic performance of large span structures.The point-supported grid frame with large stress in the local bars as the research object, this paper proposes the method to set viscoelastic damping bars in the grid frame to realize damping control of the grid structure. This report analyzes and discusses the mechanical properties and the resilience model of viscoelastic dampers, introduces the analysis methods and the design methods of viscoelastic energy dissipation structures, and proposes two damping solutions, that is, to set the viscoelastic dampers in the support column and lower chord grid nodes and replace the web member near the point supporting with viscoelastic dampers. SAP2000 and ANSYS finite element analysis software have been used to analyze node displacement, node acceleration, node speed, and rod axial force near the grid frame bearing, so as to achieve the mutual verification between analysis results. Through a comparison by changing the parameters, layout number and layout location of the dampers, the optimal layout program has been obtained, and uses nonlinear direct time integration method to analyze the damping effect of the grid structure of viscoelastic dampers under rare earthquake effect.By comparing the damping effect of four damper layout schemes, it can be found that the bigger the number of damper layout and the greater various parameters are, the better the damping effect will be, but as the number increases, the damping effect of the structure will drop significantly, so the number of damper layout in the grid structure should be appropriate. And in the grid structure, the addition of long rods between the support column and the lower grid node has better damping effect than replacement of the web member near the point bearing. The main reason is that the stiffness of the structure with web member being replaced is reduced, relative displacement and velocity at the supporting point changes slightly, and the axial force of top chord even increases slightly. The results show that when energy dissipation method is used for large-span spatial grid structure, the overall damping effect of the grid structure is better, and the internal force of most bars, the displacement, the acceleration and the speed of the nodes have been reduced. Results of this study can provide a reference for the practical application and a design of viscoelastic dampers in point-supported grid frame.