SEISMIC PERFORMANCE ASSESSMENT OF REINFORCED CONCRETE FRAME STRUCTURES BASED ON FIBER MODEL

摘要

Structures will come into an elasto-plastic phase after large earthquakes and thus can be damaged. Accurate description for the nonlinear behaviours of the reinforced concrete frame structures under seismic loads is very important to assess the seismic performance of structures. In order to achieve the accurate nonlinear behaviours of structures,an appropriate nonlinear model of components should be selected. The cross-section fiber model,which the restoring force model of elements is directly reflected through the material constitutive relationship,has aroused widespread interests. The characteristics of confined concrete,unconfined concrete and steel distribution are well reflected in the fiber model. The relationship between internal force and deformation is achieved through the integral of stress-strain relationship of fibers. In this paper,a beam-column element with fiber model based on PERFORM-3D program is established. The material stress-strain relation and the corresponding analytical parameters are determined. Then a 3-story reinforced concrete frame structure model is analyzed through the elasto-plastic time history dynamic analysis with intensity 8 and 9. The overall seismic performance of the structure is evaluated using the performance index of inter-story drift.