Parametric reduced order models for output-only vibration-based crack detection in shell structures.

• Reduced order models (ROMs) are employed to perform vibration-based crack detection. • Mesh morphing is used to parametrize the ROMs with respect to the crack geometry. • Clustering is employed to handle parametric dependence of the ROMs more efficiently. • A transmissibility based damage index is used, requiring output-only measurements. • Time series models are used to compute transmissibilities from noisy measurements. In this work parametric reduced order models (pROMs) for cracked shells are developed and applied to crack detection problems. Mesh morphing is employed to allow for parameterization of the models with respect to the crack location and size, while a clustering approach is adopted to partition the parameter space in sub-domains, for which efficient local reduced order models (ROMs) are constructed. Subsequently, the proposed ROMs are employed as forward simulators within an inverse problem setting, aiming to identify the location of the fault (crack). An output-only scheme is adopted, in the absence of information regarding the loading time history, based on transmissibility functions. The resulting scheme is tested through numerical examples involving realistic geometries, consisting of curved shells or multiple components. [ABSTRACT FROM AUTHOR]