Seismic Performance Design Methord Of The Large Scale Main Truss-Curved Face Spatial Grid Structure

With the economy prosprity of our country and satisfying rising travel demand of citizens, lots of airports in many cities and metropolises are under construction or expansion. The large scale roofs are becoming more and more complex and the spans are getting larger and larger. Issues such as how to judge the seismic response, how to imporve seismic performance of large scale roof structures deserver more attention in large scale roof structures design.Lanzhou Zhongchuan Airport New Terminal structure is used as the background project of the thesis. The tagets of this dissertation are to research the seismic performance design method of the large scale main truss-curved face spatial grid structure and approaches to impove the seismic performance of the structure. A series relative researches, such as static analysis, three-dimensional time history analyses with or without friction pendulum bearings (FPB) are finished with the help of the general FEA software MSC.Marc. And a seismic performance design method for the roof structure is brought out in the thesis. Main research results are below:(1) Researches about seismic performance evalutation indicators of the large scale main truss-curved face spatial grid structure. In the dissertation, several analyses including static analysis, three-dimensional time analyses (8-degree frequent earthquake,8-degreee rare earthquake,9-degree rare earthquake) are utilized to explore the structure's seismic performance. In analyses, the roof shear force, the number of yielded members, the roof member stress and the node displacement, weak member stress, the weak node displacement are chozen as indicators to finish the seismic performance judegement research. From analyses results, indicators mentioned above are quite efficient to judge the seismic performance of such kind of structure. With the increase of the earthquake intensity, the number of yielded members raises, and the level of members stresses and the level of nodes displacements increase in different growth. The damage of the roof structure expand with the increase of the earthquake intensity. Besides, using higher strenth materials cannot improve the structure's seismic performance.(2) Researches about friction pendulu bearings (FPB) simulation in MSC.Marc. The coding of a user subroutine is finished to simulate this FPB model in the FEA software MSC.Marc. The horizontal stiffness of the FPB element is a kind of bilinear model whose stiffness can change with the altering of FPB's vertical press. In order to meliorate the roof structure's seismic performance, some improvements are added into the existing FPBs. So an improved FPB are brought out to suit the New Terminal Roof Structure. The failure criterion of the FPB is also discussed in the thesis. And a seismic isolation layer design method for the large scale main truss-curved face spatial grid structure is also built in the thesis.(3) Researches about the roof structure seismic performance design method and improvements of the large scale main truss-curved face spatial grid structure's seismic performance. A design method is put forward to improve the roof structure's seismic performance. In the method, a kind of improved FPB is used to enhance the performance of the roof structure. Results which derive from time history analyses (8-degree rare earthquake,9-degreee rare earthquake and different earthquake waves) are collected to evaluate the seismic performance. Results include the shear force, the number of yielded members, the member stress and the node displacement, the weak member stress and the weak node displacement, etc. And energy dissipation is also used to evaluate the whole structure's performance. Results show that, the improved FPBs ameliorate the roof structure's seismic performance and protect the structure effectively in large earthquakes. The seismic performance design method is quite simple and convenient. And the design method meets the accuracy requirement.