Application of softened truss model with plastic approach to reinforced concrete beams in torsion

The present paper discusses the behavior of the reinforced concrete beams s ubjected to torsion by applying the endochronic plastic model in conjunctio n with the softened truss model. The endochronic constitutive equations are developed to describe the behavior of concrete. The mechanical behavior of concrete is decomposed into hydrostatic part and deviatoric part. New defi nition of the bulk modulus and the shear modulus are defined in tenus of co mpressive strength of concrete. Also, new deviatoric hardening function is developed. Then, the endochronic constitutive equations of concrete are app lied with the softened truss model for the behavior of the reinforced concr ete beams subjected to torsion. The theoretical results obtained based on t he present model are compared with the experimental data. The present model has shown the ability to describe the behavior of reinforced concrete beam s subjected to torsion.