| Steel structure system with specially shaped columns is a steel structure system with specially shaped column (cruciform shaped, T-shaped, L-shaped) instead of general cross-section column (Box-shaped, H-shaped), which has practical significance in promoting housing industrialization.Sponsored by the National Natural Science Foundation of China (NSFC) program(#50878008), this dissertation summarizes the characteristic of steel structure system with specially shaped columns, analyses the predominance of steel structure with specially shaped columns rather than steel structure with general section columns and concrete structure with specially shaped columns, and aiming at the researching situation about steel structure with specially shaped columns in academia, which is still in primary stage and the seismic behavior is very little involves, puts forward practical problems of steel structure system with specially shaped columns to be solved thoroughly and immediately. By Finite-element analysis study combining with experimental research, the seismic behavior of steel specially shaped columns, of steel specially shaped column with T-section to steel beam connections, of steel plane frame with T-section specially shaped columns coming from multi-story or high steel frame structure in meizoseismal area have been investigated comprehensively in this dissertation, which can provide pratical engineering applications and design specification for steel structures with specially shaped columns.Research on deformation properties, failure mode, seismic behavior and limit value of plate width-thickness ratio of steel specially shaped columns with cruciform section under strong seismic load. Basing on finite-element analysis of 36 models of steel specially shaped columns bearing low cyclic bending and constant axial compression, this dissertation simulated the entire process of their forcing, deformation and destruction, studied their seismic behavior such as bearing capacity, hysteretic behavior, energy-dissipation capacity and so on, also analyzed the influencing rule of flange width-thickness ratio, web depth-thickness ratio and axial compression ratio on the seismic behavior, and evaluated the holistic seismic behavior of those models. Finally, according to the requirements of seismatic bearing capacity and holistic seismic performance, this dissertation proposed the limit values of flange width-thickness ratio and web depth-thickness ratio under different axial compression ratio for application of steel specially shaped columns with cruciform section in meizoseismal area.Research on deformation properties, failure mode and seismic behavior of steel specially shaped columns with cruciform section under strong seismic load. The pseudo-static test on 8 steel specially shaped column models with cruciform section, 8 steel specially shaped column models with T-section, 8 steel specially shaped column models with L-section, having 1:2 geometrical scale and equal stress under cyclic loading is introduced. And then, the deformation properties, the failure model are discussed, and the hysteretic loops, skeleton curves, bearing capacity, ductility and energy-dissipation are studied. As a result, the effect of flange width- thickness ratio, web depth-thickness ratio and axial compression ratio are reviewed. At the same time, the finite-element theoretical analysis are finished. The experimental results are close to the finite-element analysis results, which shows that the steel specially shaped columns with cruciform section, or T-section, or L-section have excellent bearing capacity, good ductility and energy dissipation if certain flange width-thickness ratio, web depth-thickness ratio and axial compression ratio conditions are appropriate. Its failure model is local buckling instability failure with plenty plastic deformation. Study evidence show that steel specially shaped columns with cruciform section, or T-section, or L-section can be used in meizoseismal area.Research on deformation properties, failure mode and seismic behavior of steel specially shaped column with T-section to steel beam connection under strong seismic load. The pseudo-static test on 3 steel specially shaped column with T-section to steel beam connection models of full-scale is introduced. The deformation properties, the strain distribution, the failure model are discussed, and the hysteretic loops, skeleton curves, bearing capacity, shear deformation of panel zone, rotation, ductility and energy-dissipation are studied. As a result, the effect of panel-zone's thickness are reviewed. Testing results indicate that the steel specially shaped column with T-section to steel beam connection has strong and steady bearing capacity, excellent plastic rotational performance, good ductility and energy-dissipation. Finite-element analysis were conducted on material nonlinearity, geometric nonlinearity and contacting nonlinearity, and the results are close to those from the tests. The typical failure mode was local buckling instability with sufficient plastic deformation, the plastic hinge with being fully developed occurred at the beam far away from the wedding of column-to-beam. Study evidence shows that steel specially shaped column with T-section to steel beam connection can be used in meizoseismal area.Research on deformation properties, failure mode and seismic behavior of steel plane frame with T-section specially shaped columns under strong seismic load. The pseudo-static test on 3 steel plane frame models with T-section specially shaped columns is introduced, which are equal-stress and 1:2 reduced scale. The deformation properties, strain distribution, distribution of plastic hinge and appearance order, failure model are discussed, and the seismic behavior indexes such as hysteretic loops, skeleton curves, bearing capacity, ductility, energy-dissipation, strength-degradation and stiffness-degradation are studied. Besides, the corresponding influencing factors and regulations are reviewed. Finite-element analysis is carried out based on material nonlinearity, geometric nonlinearity. The experimental results are closed to the finite-element analysis results, which shows that the steel frame with T-section specially shaped column has strong and steady bearing capacity, slow strength-degradation and stiffness-degradation, good ductility and energy-dissipation. The typical failure mode is local buckling instability with sufficient plastic deformation under strong seismic load. When it's destroyed, the plastic hinges with being fully developed are being at the beam-end and column-feet far away from the wedding of column-to-beam and column-to-motherboard, all connections are good as well. Study evidence shows that the steel frame with T-section specially shaped column can be used in meizoseismal area. The study results of the plane frame validate the correctness and universality of the study results of steel specially shaped column and connections with steel specially shaped columns.In conclusion, focusing on the columns, connections, frames in steel structure system with specially shaped columns in meizoseismal area, the paper studies the failure mode of structure under strong seismic load, gets a series of seismic behavior indexes and corresponding influencing factors and regulations, testifies that steel structure system with specially shaped columns can be used in meizoseismal areas, and obtains corresponding research results. Finally, the paper presents some deepening problems'prospects of steel structure system with specially shaped columns.This dissertation can provide background for the seismic design of engineering and compilations of Technical Specification for steel structure with specially shaped columns. Also those research results has important theoretical significance and practical value in engineering applications.
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