Cording to the measured data from the Fenshuiling tunnel of Lingnan freeway, the elastic modulus of tunnel surrounding rock and the horizontal crustal stress are back calculated with the system identification method. The results indicate that it is reasonable and the inversion procedure has stronger adaptive control,good convergent calculation stability,rapid calculation velocity. It shows that the system identification method to back calculate the elastic modulus of tunnel surrounding rock is effective.
Modal parameter estimation plays an important role in vibration-based damage detection and is worth more attention and investigation, as changes in modal parameters are usually being used as damage indicators. This paper focuses on the problem of output-only modal parameter recursive estimation of time-varying structures based upon parameterized representations of the time-dependent autoregressive moving average (TARMA). A kernel ridge regression functional series TARMA (FS-TARMA) recursive identification scheme is proposed and subsequently employed for the modal parameter estimation of a numerical three-degree-of-freedom time-varying structural system and a laboratory time-varying structure consisting of a simply supported beam and a moving mass sliding on it. The proposed method is comparatively assessed against an existing recursive pseudolinear regression FS-TARMA approach via Monte Carlo experiments and shown to be capable of accurately tracking the time-varying dynamics in a recursive manner.
Output-Only Modal Parameter Recursive Estimation of Time-Varying Structures via a Kernel Ridge Regression FS-TARMA Approach