A scenario-based damage identification framework

Abstract

Damage has a direct impact on the modal parameters of structures. However, finding the location and severity of the damage from the modal parameters is a challenging task. This is because damage identification problems are in general highly undetermined, i.e. the number of potential damage locations is much higher than the size of the experimental data set. The presented damage scenario-based framework overcomes this problem by both increasing the size of the experimental data set and reducing the number of investigated damage locations. The key component of the damage-scenario based approach is an FE-model of the undamaged structure that has been updated in a physically correct way, i.e. no equivalent parameter changes were made to update the model. Such a model can be obtained by correcting the FE-geometry using a high fidelity geometrical description of the test structure, before updating the mass and stiffness parameters. The updated FE-model can provide relevant information on the damage scenarios that can be expected and this for a relatively wide frequency range. Furthermore, as no equivalent parameter changes were made during updating, the updated model can also be used to predict the effect of these damage scenarios on the modal parameters. As such, the damage detection problem can be redefined as a decomposition problem: decompose the observed shift of the modal parameters into the contributions of the considered damage-scenarios. © The Society for Experimental Mechanics, Inc. 2012.