| Title |
Seismic Design of Buckling-Restrained Braced Frames Based on the Modified Equivalent Energy Concept |
| Authors |
Choi Hyun-Hoon ; Kim Jin-Koo |
| Keywords |
Equivalent Energy Concept ; Buckling-Restrained Brace ; Hysteretic Energy ; Seismic Design |
| Abstract |
There are some problems in the equivalent energy concept (EEC) proposed by Housner as follows: (i) The use of pseudovelocity for estimation of the input seismic energy sometimes underestimates the input energy demand. (ii) The input energy of inelastic system is not equal to that of equivalent elastic system. (iii) The plastic to input energy ratio estimated by the EEC is larger than that by time history analysis. In this study seismic design procedure for buckling-restrained braced frames was proposed using modified EEC considering above problems. The design process begins with the computation of input energy from response spectrum. Then the computed plastic energy based on the modified EEC is distributed to each story along energy distribution ratio and the area of each brace is computed so that all the plastic energy is dissipated by the brace. The proposed procedure was applied to the design of 3-, 6-, and 8-story steel frames with buckling-restrained braces for three different performance targets, and 20 earthquakes were utilized for verification of the proposed method. According to analysis results, top story displacements correspond well with the given performance targets. |