Seismic Behaviors Research On Diagrid Tube Substructure Standard Unit

Diagrid tube strucrtural system as a new and efficient structural system,is consisting of the outside tube which component is continuous two-way cross inclined column around the building and the core tube. The two-ways cross inclined column of the structural system with a very powerful lateral stiffness bear the horizontal and vertical loads. The diagrid tube structural system is different with the conventional structural system in terms of structure form and stress mechanism.The pushover analysis of diagrid tube strucuture and standard unit substructure are carried out, the component yield sequence, yield mechanism of inclined column, failure mode are given. In order to understand the seismic behavior of diagrid tube structure, the study of pseudo-static experiment for the scale model of diagrid tube structure containing two standard unit substructures. The hysteresis curve and skeleton curve are obtained, on the basis of the curves, the ductility coefficient, capacity degradation and stiffness degradation rules, energy dissipation, etc are studied. Through the real-time monitoring of coupling beam, the yield sequence, the failure mode of outsid tube, the yield mechanism of are analyzed. The results show that the component yield sequence is coupling beam, inclined column of outside tube, the core tube bottom shear wall, the yield mechanism of inclined column is axial force, the plastic areas develops from the web to two flanks, and from the sides to the middle, from bottom to top in outer net tube.The numerical analysis by ABAQUS for the diagrid tube standard unit substructure is carried out. The results of the numerical analysis is agree well with the experimental results, which show the correctness of the experiment study, also shows the finite elment modelling method is correct. In order to improve the deformation capacity and introduce beam component bending yield mechanism, four diagrid tube structural systems with different grid forms are modeled, the one-way loading and cyclic loading are made. The yield order of each component, yield mechanism of column in outer net tube, the internal force distribution charactristics of four diagrid tube structural systems, etc are obtained. The results show that by cutting off force transfer path of the outside tube and introducing bending moment mechanism are helpful to improve the yield mechanism and ductility of diagrid tube structure, The three diagrid tube structural systems with different grid forms are the same with conventional tube-in-tube strural system in force mechanism.