Identification Of Nonlinear Structural Parameters Of The Bouc-wen Model

In the field of structural control and health monitoring for nonlinear structures, the parametric identification of nonlinear structures is very important. Based on the Bouc-Wen model, the parametric identifications of nonlinear structures are completed in this paper.The parameter analysis method of Bouc-Wen model is introduced, and the effects of the parameters in the model on the shape of the hysteresis loop are studied using the numerical simulations. The nonlinearity detection principle through Hilbert transform is illustrated, and the root-mean-square error between the amplitude curve of the structural frequency response function and its Hilbert transform is presented as the relative index to quantify the nonlinearity of structures. The on-line identifications of nonlinear structures with Bouc-Wen model and structures with certain abrupt changes in the structural parameters are studied based on the new on-line identification algorithm for nonlinear structures.Results show that Bouc-Wen model can simulate the typical nonlinear hysteresis characteristics in engineering. Hilbert transform can detect the nonlinearity of structures, and the presented index for structural relative nonlinearity can approximately indicate the excitation level when structures occur certain nonlinearity, and reflect the damage of structures. The on-line identification algorithm can identify the nonlinear restoring force and the changes in structural parameters in real time.