Baseline-free localization and quantification of structural damage using spectral response

Localization of damage using modal parameter changes has been the focus of research in many recent studies. Efforts have also been made to establish an analytical correlation between changes in modal response from the healthy state and the eventual reduction in stiffness. Prevailing methodologies predominantly integrate baseline responses to attain these objectives. However, non-availability of pre-recorded data practically complicates the application of reference state- based damage investigations. In the present study, a novel formulation is proposed for evaluation of existing crack with spectral responses of only damaged state. Efficiency of derived mathematical formulation is numerically verified on a shear building with several damage cases. Robustness of the method is then examined through noise sensitivity analysis. Further, an experimental investigation is conducted on a reduced scale in-house steel building model. Two cases of damage severity are examined by introducing reduced cross-sectional member at the damage location. Finally, practical applicability of the method is explored with a case study using real post-damage data of a 7-story building. Significant accuracy evolved from these exhaustive analyses, highlights the potential of present baseline-free damage quantification technique. This instantaneous data- based methodology can further be extended in future to assess residual useful life of a structure.