PARAMETER-IDENTIFICATION FOR DEGRADING AND PINCHED HYSTERETIC STRUCTURAL CONCRETE SYSTEMS

Hysteretic models are frequently used to predict the non-linear behavi or of reinforced concrete structural systems. Such models are typicall y characterized by control parameters that have to be calibrated from observed experimental testing. A system identification methodology is presented in this paper for determining the values of control paramete rs in a continuously smooth hysteretic model for inelastic dynamic beh avior of structural concrete systems, The technique is based on a modi fied Gauss-Newton approach in which a non-linear relationship between model parameters and the force-deformation or moment-curvature hystere tic loops is assumed. The methodology is applied to an extended versio n of the well known rate-dependent Bouc-Wen hysteretic model, Six cont rol parameters are introduced into the model which influence the degra ding characteristics and, therefore, represent the target parameters t hat need to be optimized. The versatility of the approach is demonstra ted through sample simulations of observed behavior which are drawn fr om reinforced and partially prestressed concrete elements and subassem blages including beams, columns and beam-column joints. Studies of con vergence of the proposed algorithm and sensitivity of the model to ide ntified parameters is presented. Copyright (C) 1996 Elsevier Science L td.