Subspace identification of bridge dynamics via traversing vehicle measurements

This study establishes a subspace identification scheme to estimate bridge frequencies by processing the dynamic response of a traversing vehicle for two traverses over the target bridge. Specifically, this study discusses the feasibility of the Multivariable Output Error State Space (MOESP) method for vehicles with high speed and/or bridges with short characteristic lengths. To deal with the time-varying nature of the vehicle-bridge system, the study employs the singular value decomposition (SVD) based pseudo-inverse algorithm. The proposed scheme numerically verified on synthetic datasets, which are attained via simulation of the vehicle- bridge interaction (VBI) problem, in order to obtain the vehicle response, which serves for application of the MOESP algorithm. The numerical experiments concern both a sprung mass vehicle and a more realistic multi-degree-of-freedom (MDOF) vehicle identifying a 3-span bridge. The results demonstrate that the proposed approach succeeds in identifying structural frequencies of the bridge even under assumption of high vehicle speeds and high levels of road surface roughness.

Automated summary

This study proposes a subspace identification scheme to estimate bridge frequencies by processing the dynamic response of a traversing vehicle, specifically discussing the feasibility of the MOESP method for vehicles with high speed and short characteristic lengths. The study uses a SVD-based pseudo-inverse algorithm to deal with the time-varying nature of the vehicle-bridge system, and numerically verifies the proposed scheme on synthetic datasets obtained via simulation of the VBI problem.