Secondary Development Of Elasto-plastic Response Analysis Program And Seismic Performance Verification For Frame-wall Structures

On the basis of previous studies, frame-wall structures are analyzed by macro models which can't consider well coupling action of bending , axial effect and shear effect, so there are many disadvantages in elasto-plastic response analysis of frame-wall structures when structures have severe damage. Aiming at the problems mentioned above, concrete material subroutines basing on the ABAQUS beam element were secondary developed. An effective way basing on these subroutines and shell element to carry out inelastic response analysis of frame-wall structures was provided. Then it was verified by simulating the experiment result. And then, the method provided above was used to carry out pushover and dynamic time-history analysis, studying on the structure failure process, the developing of the bottom plastic-hinge region and shear- force in columns, and distribution law of inter-story displacement angle.According to the analysis carried out above, the conclusions are as following:â‘ Concrete material subroutines secondary developed have good accuracy and convergence, the concrete material models of ABAQUS were effectively expanded. And the inelastic response analysis method basing on these subroutines is effective.â‘¡For the frame-wall structure adopted in this thesis, under pushover analysis, in state of small and medium earthquake performance, the maximum inter-story displacement angle located in central floors; in state of big earthquake performance, walls and columns in strengthened region at the bottom yield gradually, and deformation concentrated, the maximum inter-story displacement angle located in second floor. Under the dynamic time-history analysis, the response of the frame-wall structure is different , it is not controlled by the first vibration mode, it relates to spectrum characteristics of the ground motion and dynamic characteristics of the structure, therefore, distribution law of inter-story displacement angle was different under different ground motion, but maximum inter-story displacement angle located in bottom floors under large earthquake.â‘¢Under pushover analysis, in state of big earthquake performance, the strengthened region was higher than the plastic-hinge region at the bottom, the internal force shifting to upper floors was not obvious; Under large earthquake dynamic analysis, the damage of bottom walls was large, but the damage of walls in other floors was also large, sometimes larger than the bottom walls. The strengthened region was not higher than the plastic-hinge region at the bottom, but conclusively, it meets the requirements of no collapsing with large earthquake.â‘£Under all the inelastic response analysis, with increase of the intensity of ground motion, internal force was redistributed, shear-force in columns increased gradually, proportion in total force increased from almost 20% to more than 40%. Under medium earthquake, steel in columns did not yield or just yielded; under large earthquake, damage of columns concentrated at the bottom and top floors, damage at the other floors was not great, columns could be the second fortification line for earthquake.