Seismic Response of Reinforced Concrete Frames Using Non Linear Macro-Element Behavior

Abstract

This chapter deals with the computation of reinforced concrete frame structures with a simplified method, using non linear macro-elements. A multi-level approach based on the notion of macro-element is discussed in the chapter. This approach brings the rapidity of an analysis with a reduced number of degrees of freedom, while relatively keeping the refinement of a local analysis. Concerning the dynamic aspect, a method of analysis that uses a step-by-step integration method and whose objective is an evaluation of the nonlinear seismic response of structural systems, using a modal superposition technique that greatly decreases the required computational effort, is passed. The assumption that is given out is that the non linear terms of the equations of motion can be considered, without any simplification, as additional external forces, and thus, the resulting equations of motion can be physically interpreted as the equations of motion of a conventional linear system excited in its base by a modified ground motion. The chapter presents some numerical examples that demonstrate the accuracy, as well as the effectiveness of the method. The approach proves effective for cyclic, as well seismic loadings, and allows a person to correctly describe the evolution of degradations.