Papers by Author: Shu Yun Zhang

Abstract: Considering core thickness is important issue to performance of exterior frame and core hybrid structure in high-rise buildings, seismic response analysis is conducted by response spectrum method for finite element models with different core thickness. The optimization design of core thickness of hybrid Structures on the basis of the seismic response is studied, the core thicknesses are chosen as design variables, the objective function about core volume is adopted, some specification requirements such as deformation, the ratio of lateral stiffness to gravity, storey shear to gravity, storey shear of exterior frame, axial compression ratio of column and wall limb, bearing capacity of structural member and core construction are regarded as restricting conditions, the optimal mathematical model is established for reflecting integrity dynamic properties of hybrid structure. The ANSYS software is used for optimizing tool, the hybrid structures optimization design are made through different initial values for verifying convergence of optimization method, the optimal result show that the performances of hybrid structure are improved, the internal forces are reduced and the ratios of inner force born by exterior frames are increased in the optimal scheme.

Abstract: For seismic design of composite frame and reinforced concrete core hybrid structures in high-rise buildings, the response spectrum method is influenced to a large extent by mode combination rules and number of combined modes. The dynamic characteristics of composite frame and concrete core hybrid structures were studied through modal analysis, natural vibration periods and mode shape of hybrid structures had calculated and analyzed, the results show that the natural vibration frequencies are near, the complete quadratic combination of mode combination rule was recommended for avoiding higher order mode shape lose in the response spectrum method. The reasonable number of combined modes for response spectrum method were studied by truncation error analysis, it is proposed that more than 20 modes are combined. The results of the time history analysis und The three dimensional finite element er three earthquake waves were compared with results of response spectrum, indicating that the maximum response of hybrid structures can be obtained under reasonable mode number.

Abstract: For mechanical behaviors of composite frame and reinforced concrete core hybrid Structures in high-rise buildings, the three-dimension finite element models were established, modal analysis and elastic time-history analysis were finished, the cooperative work mechanism between frame and core was researched, the dynamic characteristics and seismic response of the hybrid structures under different connection type were studied. the results indicate that the stiffness characteristic of the hybrid structures should be taken between 1 to 2 so that two sub-structure can reasonably afford the internal force, the connection between frame and core bring differences in mode shape and natural vibration periods, the natural vibration periods of hinged model are greater than periods of rigid model, the mode shapes with mainly floor vibration are more likely to appear in hinged model, the connection would lead to significant changes in the deformation and distribution of inner force, the axial force of frame columns would significantly increase for the rigid connection, the shear and bending moment of frame columns would increase for the hinged connection, it was proposed that the hybrid structures should be separately analyzed with hinge model and rigid model for ensuring the frame columns have sufficient capacity of the shearing and bending both.