NONLINEAR CREEP ANALYSIS METHOD FOR CONCRETE STRUCTURES

The concrete nonlinear creep constitutive rule and the analysis method have studied for the accurate calculation of a long-term deflection and for the stressed condition of the concrete structures with defects. Based on the nonlinear elastic creep law, the stress softened coefficient is induced according to a Hongnestad model, and a new nonlinear creep constitutive model is presented. By the initial strain method, the creep incremental strain iteration is accomplished, considering the concrete material nonlinear effects. The linear coupling between creep and cracking is assumed for taking into account the development of cracking with time. The new material-model is implemented into the Adina user-supplied subroutine. Through comparing the analytical results to the classical experimental results, it is verified that the calculation method is reliable.