| Mega-frame structure is a new and efficient structure system which has good prospects for development. However, the theoretical and experimental research, and the engineering application are still in initial stage in China, many difficult issues need to be researched. In this paper, with the support of National Natural Science Foundation project " Research on Seismic Energy and Collapse Analysis of Super High-Rise Mega-frame Structures with Vibration-Absorption " (No:51378167), the research were carried out with the method-QR method for analyzing mega-frame structure. It ranges from reinforced concrete mega-frame structure to giant composite frame structure, from static analysis to seismic response analysis, covers the theory of QR method and its engineering application in mega-frame structure. The simplification for QR-method and its program implementation are discussed as well.Chapter 1 provides a brief introduction to the characteristics of mega-frame structure, the engineering application and research status both at home and abroad, thereafter, summarizes the study and application of QR method for structure analysis. Finally, the main research content of the paper was pointed out.Chapter 2 discusses the basic principle of QR method. The basic concept of spline function and the construction of spline basis function, structural discretization and spline discretization, the analytical procedure and characteristics of QR method were introduced. The simplification for the method the program implementation, and treatment measures for irregular structure, which lays the theoretical foundation for structural analysis in subsequent chapters.Chapter 3 carries out the application of QR method for reinforced concrete mega-frame structure. After introducing the simplified mechanical model of mega-frame structure, the stiffness matrix and the formula of the fixed-end force under the influence of rigid area and shear deformation were researched. The calculational steps for static analysis of mega-frame structure based on QR method and its program design were pointed out in detail. According to calculation and analysis for some examples, study was carried out on performance of mega-frame structure with the influence of rigid area and shear deformation effect, QR method and the corresponding computational procedure are effective and feasible to analyze reinforced concrete mega-frame structure as well.Chapter 4 has a discussion on analysis of giant composite frame structure based on QR method. The fundmental theorem of semi-rigid connection was introduced, then computation about the element stiffness matrix and load vector considering semi-rigid connection were studied. A general element stiffness matrix for different element was established. According to calculation and analysis of typical examples, the influence on structure performance under different node connection type is analyzed; QR method and the corresponding computational procedure are proved to be an effective and feasible method for calculating and analyzing the mega composite frame structure.Chapter 5 discusses the seismic response analysis of mega-frame structure based on QR method. The element mass matrix considering the effect of shear deformation was deduced. The new calculation format of seismic response analysis for the mega-frame structure was established, and the procedure was illustrated. Through calculation and analysis for some typical examples, the method is proved to be a kind of economic, effective and feasible method for structure analysis, which provides a new way for seismic analysis of mega-frame structure.Chapter 6 gives the summarization and prospect on the research work in this article, points out the main innovation points and research direction in the future at the same time.The main research results are as follows:(1) Based on cubic B-spline cardinal function, a new cubic B-spline cardinal function, which is used to construct structural displacement function, is deduced.(2) The concept of ’equivalent spline partition step (ESPS)’ is put forward. Then, the spline-node number can be determined directly by node coordinates in structures according to the mathematical integral function, which makes it possible to compute the irregular structure by the simplified QR method.(3)According to the energy variational principle, the element stiffness matrix and load array for space beam element considering shear deformation effect is derived, which lays foundation for the static and seismic analysis procedures of reinforcement concrete mega-frame structure and mega composite frame structure..(4) The influence and treatment measure on the plane and space beam element stiffness matrix and fixed end force calculation while considering the nodal rigid area was analyzed.(5) The element stiffness matrix and the calculation formula of the fixed end force of plane beam with arbitrary connection were discussed. Based on the planar beam, the space beam element stiffness matrix considering node any connection type was constructed(6) According to the characteristic of giant composite frame structure, the general element stiffness matrix for planar and spatial beam which consider different connection, node rigid area, and the shear deformation effect was constructed, which gives convenience to the calculation program development of mega composite frame structure.(7) The new computing format of static and seismic analysis for the mega-frame structure was established, and the corresponding calculation programs were written in MATLAB. According to comparative analysis of some typical examples, It verifies the accuracy of corresponding assumptions and calculation programs, and points out that the QR method is feasible and effective for the mega-frame structure analysis. |
PDF Full Text Request