Fundamental periods of steel concentrically braced frames designed to Eurocode 8
Article first published online: 7 JAN 2013
Copyright © 2013 John Wiley & Sons, Ltd.
Earthquake Engineering & Structural Dynamics
Volume 42, Issue 10, pages 1415–1433, August 2013
How to Cite
Günaydın, E. and Topkaya, C. (2013), Fundamental periods of steel concentrically braced frames designed to Eurocode 8. Earthquake Engng. Struct. Dyn., 42: 1415–1433. doi: 10.1002/eqe.2279
- Issue published online: 9 JUL 2013
- Article first published online: 7 JAN 2013
- Manuscript Accepted: 3 DEC 2012
- Manuscript Revised: 15 NOV 2012
- Manuscript Received: 18 JUN 2012
- concentrically braced frame;
- fundamental period;
- Eurocode 8
A two-phase research program has been undertaken to investigate fundamental natural periods of concentrically braced frames (CBFs) designed according to Eurocode 8 (EC8). In the first phase of the program, over 83,700 buildings were designed, and the accuracy of the lower bound expressions given in well-known design specifications was evaluated. The results indicated that the lower bound expressions given in EC8 and National Building Code of Canada (NBCC) are acceptable. Although all structures had periods longer than the ones estimated by the EC8 expression, a few structures had shorter periods than the ones estimated by the NBCC expression. In general, the lower bound expressions given in EC8 and NBCC were found to provide over conservative estimates for most cases. In the second phase of the program, a simple hand method was developed to estimate the fundamental natural periods of CBFs designed to EC8. This method requires the use of inelastic top story drift ratio as a parameter to quantify stiffness characteristics. The drift ratios were extracted from the design pool developed as a part of the first phase and represented by simple mathematical relationships. Evaluation of the proposed method indicated that the method is accurate in providing estimates of the fundamental period. To safeguard against providing unconservative estimates, the method was modified to arrive at a new lower bound expression, which significantly improves the estimates compared with the ones provided by the existing expressions. Copyright © 2013 John Wiley & Sons, Ltd.