Non-model based structural damage assessment using improved analytical redundancy relations

Abstract

A damage assessment problem can be stated as a constraint satisfaction problem utilizing the translational and rotational displacements of a structure as measurements. By this means, usual numerical models are no longer required for a damage assessment, which considerably simplifies the solution process. In order to avoid the use of rotational displacements that are difficult to measure in practice, an improved analytical redundancy reduction method has been developed in which rotational displacements are replaced by translational ones. Moreover, some constraint equation positions in the decomposition of a static equilibrium matrix are exchanged according to their association with pre-assumed damaged elements. Then damage is located according to the changes in the relevant constraints of specific elements or substructures. Besides, the deviation increments of improved analytical redundancy reduction can embody the stiffness changes of the damaged elements. The proposed improved analytical redundancy reduction method was validated using both numerical and experimental steel box beams under static loads. The damage assessment results demonstrate the superiority of the improved analytical redundancy reduction method over the constraint satisfaction problem and analytical redundancy reduction methods.