Modeling of physical non-linearity of reinforced concrete elements under long - term loading

Abstract

The paper presents a method of modelling of material non - linearity for use in analysis of load - carrying capacity and strains of reinforced concrete beams, and membrane - bending plates subjected to long - term loads. Physical relationships expressing relations between internal forces and stresses, strains and stiffness are derived on the basis of the fracture and creep theories for concrete and using non - linear stress - strain diagrams modified for time effects. A genetic algorithm is used to find multiple solutions of considered non - smooth problems. The computation technique proposed is found to be effective by numerical examples, and an adequate accuracy of the analysis is verified by comparison with experimental data.