ABSTRACT

Abstract The inverse of q-factor in ECS and the Ds-value in Japanese building code are equivalent and signify a strength reduction factor ascribed to the energy absorption capacity of a structure. Despite that these strength reduction factors have been deemed to be an empirical one, the logical framework to estimate the strength reduction factor must be established for the sound development of the earthquake resistant design based on the energy concept. In this paper, an outlined feature of the strength reduction factor is presented and comments on papers presented at the Workshop are added in the light of theoretical derivation of the strength reduction factor. Keywords: Energy concept, q-factor, Ds -value, cumulative inelastic deformation ratio, inelastic deformation ratio, damage concentration,? - 8 effect,global ductility,local ductility.