Structural Nonlinear Damage Identification Method Based on the Kullback–Leibler Distance of Time Domain Model Residuals

Under external load excitation, damage such as breathing cracks and bolt loosening will cause structural time domain acceleration to have nonlinear features. To solve the problem of identification, a identification method based on Kullback–Leibler (KL) distance model residuals is proposed in this paper. First, an autoregressive (AR) order was selected using autocorrelation function (ACF) Akaike information criterion (AIC). Then, AR obtained response series, residual extracted. Finally, KL used indicator judge source location. The effectiveness verified by multi-story, multi-span stand experiment simulated eight-story shear structure. results show that can effectively distinguish location multi-degree-of-freedom structures complex structures, it robust enough detect environmental noise small damage.