A carregar...
PublicaĆ§Ć£o
Damage identiļ¬cation in beams using speckle shearography and an optimal spatial sampling
| Nome: | DescriĆ§Ć£o: | Tamanho: | Formato: | |
|---|---|---|---|---|
| 3.08 MB | Adobe PDF |
Orientador(es)
Resumo(s)
Over the years, the derivatives of modal displacement and rotation ļ¬elds have been used to localize damage in beams. Usually, the derivatives are computed by applying ļ¬nite differences. The ļ¬nite differences propagate and amplify the errors that exist in real measurements, and thus, it is necessary to minimize this problem in order to get reliable damage localizations. A way to decrease the propagation and ampliļ¬cation of the errors is to select an optimal spatial sampling. This paper presents a technique where an optimal spatial sampling of modal rotation ļ¬elds is computed and used to obtain the modal curvatures. Experimental measurements of modal rotation ļ¬elds of a beam with single and multiple damages are obtained with shearography, which is an optical technique allowing the measurement of full-ļ¬elds. These measurements are used to test the validity of the optimal sampling technique for the improvement of damage localization in real structures. An investigation on the ability of a model updating technique to quantify the damage is also reported. The model updating technique is deļ¬ned by the variations of measured natural frequencies and measured modal rotations and aims at calibrating the values of the second moment of area in the damaged areas, which were previously localized.
DescriĆ§Ć£o
Palavras-chave
Multiple damage Finite differences Optimal sampling Modal rotation Shearography Model updating
Contexto Educativo
CitaĆ§Ć£o
Editora
Elsevier