Flat-slab building structures exhibit significant higher flexibility compared with traditional frame structures, and shear walls (SWs) are vital to limit deformation demands under earthquake excitations. The objective of this study is to identify an appropriate finite element (FE) model of SW dominant flat-plate reinforced concrete (R/C) buildings, which can be used to study its dynamic behavior. Three-dimensional models are generated and analyzed to check the adequacy of different empirical formulas to estimate structural period of vibration via analyzing the dynamic response of low- and medium-height R/C buildings with different cross-sectional plans and different SW positions and thicknesses. The numerical results clarify that modeling of R/C buildings using block (solid) elements for columns, SWs, and slab provides the most appropriate representation of R/C buildings since it gives accurate results of fundamental periods and consequently reliable seismic forces. Also, modeling of R/C buildings by FE programs using shell elements for both columns and SWs provides acceptable results of fundamental periods (the error does not exceed 10%). However, modeling of R/C buildings using frame elements for columns and/or SWs overestimates the fundamental periods of R/C buildings. Empirical formulas often overestimate or underestimate fundamental periods of R/C buildings. Some equations provide misleading values of fundamental period for both intact and cracked R/C buildings. However, others can be used to estimate approximately the fundamental periods of flat-plate R/C buildings. The effect of different SW positions is also discussed.

Among different approaches developed for structural damage detection, changes in the measured static response have shown promise for locating structural damage. In this paper, an analytical study of the relationship between damage characteristics (location and severity) and changes in displacement curvatures is presented. Then a parametric study is carried out on using changes in displacement curvatures in structural damage detection. The influence of many parameters are investigated and applied numerically to two examples; an overhanging beam (statically determinate structure) and a two-span continuous beam (statically indeterminate structure) with different damage characteristics. The numerical results clarify that the displacement curvature, has the characteristic of localization at the damaged region. Also, the obtained results show that the displacement curvature, derived from static response only, can accurately locate single and multiple damages with different damage characteristics for specific load case. The merits as well as the disadvantages of using displacement curvature in structural damage detection are also discussed.