INELASTIC RESPONSES OF REINFORCED CONCRETE STRUCTURES TO EARTHQUAKE MOTIONS

Two basic characteristics of reinforced concrete structures play an important role in determining response to strong ground motions. They are the changes in stiffness and energy dissipation capacity. Both can be related to the maximum displacement. Results of dynamic tests of reinforced concrete frames are used to illustrate the effects on dynamic response of changes in stiffness and energy dissipation capacity. It is shown that maximum inelastic response can be interpreted in terms of linearly elastic analysis by reference to a fictitious linear structure whose stiffness and damping characteristics are determined as a function of the assumed or known maximum displacement. This leads to a simplified method for estimating the design base shear taking account of inelastic response. The object of this paper is to describe basic phenomena of energy dissipation in reinforced concrete structures subjected to strong ground motion, and to present a simplified method for estimating the design base shear corresponding to inelastic response.