Analysis of damaged concrete frames for cyclic loads

A mathematical model for reinforced concrete frame members is presented, which is different from others presented in the literature in that the finite size of the plastic regions is taken into account. Moreover, the model requires the specification of only elementary material properties of steel and concrete to simulate the complete behaviour under strong cyclic loads. To facilitate the analysis of damaged concrete frames, element and global damage parameters are introduced which permit the estimation of all initial conditions from only a few basic variables which can be obtained from post-earthquake field inspections, such as the residual roof displacement. The accuracy of the model is demonstrated in a series of three examples wherein analytical response predictions are compared with available experimental test data.