A Hybrid Method using q-Gradient to Identify Strutuctral Damage

Reynier Hernández Torres¹; Marluce Scarabello¹; Haroldo Campos Velho¹; Leonardo Chiwiacowsky²; Aline Soterroni¹; Erica Gouvea¹; Fernando Ramos¹

¹ INPE - National Institute for Space Research; ² Unisinos - University of Vale do Rio do Sinos

doi:10.20906/CPS/CILAMCE2015-0872

Resumo

The present investigation is focused on the solution of a dynamic inverse problem which is concerned with the assessment of damage in structures by means of measured vibration data. This inverse problem has been presented as an optimization problem and has been solved through the use of the conjugate gradient method with the adjoint equation, i.e. the variational approach. The stiffness estimation problem has already been solved in a satisfactory form through the use of the variational approach, where spring-mass systems with one and two degrees-of-freedom (DOF) have been considered. However, when a higher DOF structure is considered, the simple application of the variational approach is not more satisfactory, being necessary the application of an additional methodology. This work presents a hybrid approach to overcome this difficulty, where a new optimization scheme based on q-gradient is employed to provide an initial guess for the conjugate gradient method (CGM). The damage estimation has been evaluated using simulated experimental data, and the reported results are concerned with a lumped-parameter system.

Palavras-chave: Structural damage ; Variational approach; q-gradient technique; Inverse vibration problem