Effects of Sensor Count on Damping Estimates from Operational Modal Analysis
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For fatigue estimation of many large structures the damping coefficients of the first couple of modes are the most essential. These modes can often be identified, by Operational Modal Analysis (OMA), by using a low number of sensors. However, it is not well known how the number of sensors and their locations are affecting the damping estimates provided from OMA. In this paper it is investigated how the damping estimates from OMA depend on the number of sensors and their locations. In addition, the so-called reference-based OMA methods using quadratic Hankel matrix, where only a few DOFs are used for calculations of the non-parametric functions (e.g. correlation functions), is compared to using the squared (full) Hankel matrix. All the results are presented based on experimental data.
KeywordsOperational modal analysis Damping estimation Experimental data System identification strategy
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