A bifunction criterion for structural damage detection

A new paradigm based on strain mode, displacement mode and vibration analysis for structural damage detection is proposed in this paper. Strain modes are sensitive to damage; however, they are not readily identifiable, especially in large practical structures. Consequently, a new bifunctional structural damage criterion based on indirectly obtained strain modes is derived. The derivation together with finite element method analysis is then applied to data measurable by scanning laser doppler vibrometry and the viability of the new approach demonstrated. It is analytically shown that the technique is useful for structural damage detection in beamlike structures provided displacement mode data are available. Various scenarios are presented and discussed to emphasize the modeling.