Damage identification of output-only systems by means of genetic algorithms

The present work illustrates the recent advances in the damage identification of structural systems in case of “output-only” problems. As safety evaluation and damage assessment of existing engineering structures asks for a deeper structural analysis, usually carried out through the finite element techniques, a numerical model identified in order to properly simulates the actual behaviour of the structure at hand is needed. Consequently identification procedure is an actual engineering concern. To discuss these aspects the experimental campaign conducted in a benchmark three-story steel structure at the Civil Engineering Laboratory of the University of Florence (Italy) laboratory is first reported. The structure has been tested (under ambient loading) starting from the actual configuration and imposing steps of increasingly damage level by partial cuts of flanges on some steel elements (columns). After a neural network based procedures has been proposed and adopted to analyse accelerometer signals recorded during the experimental campaign. Results are discussed and the dynamic properties of the building are evaluated at each damage level. At the end, the ongoing research step aimed to employ genetic algorithms to finite element model identification is discussed.