Modelling environmental effects on the dynamic characteristics of the Tamar suspension bridge
For structural health monitoring purposes, it has become extremely important to understand, model, and compensate for the effect of environmental variations on the dynamic characteristics of structures under their ambient operating conditions. In this paper, acceleration measurement data from the Tamar Suspension Bridge, UK, processed by the data-driven stochastic subspace identification method is investigated, and the environmental variations in the natural frequencies modelled with respect to the temperature and the wind loadings. Two different approaches are considered; 1) Principal Component Analysis (PCA) which effectively identifies a linear variation pattern induced by environmental effects and 2) meta-modelling, a purely mathematical way to find an input-output relationship of a system based on various combinations of polynomial functions. This study found that the temperature was the biggest contributor to the environmental variations of the bridge’s natural frequencies.
KeywordsWind Speed Structural Health Monitoring Bridge Deck Wind Loading Suspension Bridge
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