Title: Nonlinear RC Structure Model Updating using Ambient Vibration Data
Author(s): W. Song, M. So, S.J. Dyke, T.G. Harmon, and G.J. Yun
Publication: Symposium Paper
Appears on pages(s): 99-124
Keywords: damage detection; hysteretic material model; modal flexibility; model
updating; RC beam-column joint
A new method is proposed for updating the nonlinear finite element (FE) model of a structural system. It has been recognized that in some classes of structures, the degradation of the capacity of the structure occurs with a change in the zero-crossing stiffness. A relationship is obtained between the damage parameters used in a numerical simulation and the FE model stiffness at the zero-load crossings. This relationship is used to update the state of the FE model to reflect the damage that is associated with dynamic parameters. The modal characteristics are identified using ambient vibration data. The approach has been applied to a numerical model of a RC beam-column building subassemblage under quasi-static loading to demonstrate the proposed method. For simulation purposes, a one-dimensional hysteretic load-deformation material model is used in the FE model to represent the nonlinear moment-rotation behavior of RC beam-column joints. A modal flexibility-based model updating procedure is performed to update the damage parameters based on the change in the dynamic characteristics at each zero-load crossing. Good agreement between the updating and simulated stiffness demonstrates the efficacy of the proposed method.