Shahabodin Zaregarizi - Dept. of Civil Engineering, Amirkabir University, Tehran, Iran

One of the most important assumptions for analysis and design of building against lateral force is rigidity of floor diaphragms. This assumption decreases the degrees of freedom and makes the analysis simpler. But the application of this assumption to the seismic analysis of building structures may be not valid in many cases and make the design not safe and economical. In this study, to investigate the effect of floor rigidity, one type of steel frame including simple frame with X-braces was considered. The linear static analysis and spectral dynamic analysis both was used to investigate the flexibility of diaphragm in each case via Variables such as thickness of diaphragm, plan dimensions ratio and number of stories.

Rigid Diaphragm, Flexible Diaphragm, Steel Braced Frame, Linear Static Analysis, Spectral Dynamic Analysis