Prediction of seismic responses of buildings based on the energy concept

Performances of buildings can be generally evaluated by the energy absorption capacity developed by buildings. Energy absorption is made mainly through the inelastic deformation of structural elements. In multi-storied structures, it is essential to predict adequately the damage distribution. The P- A effect which is produced by the gravity load and the translational deformation caused by the earthquake is an important factor to impair the energy absorption. Besides the energy absorption which can be clearly evaluated in a form of the hysteretic energy absorption, it is general to introduce empirically a kind of viscous damping. However, the handling of the damping always is accompanied by some ambiguities. Although still exist various uncertain points in regard to the energy absorption, in this paper, the structural behavior of buildings is described generally and most-compactly and the arrived point in evaluating seismic performances is made clear.