Vibration Structural Damage Diagnosis Based on Modal Parameters

Vibration structural damage diagnosis is crucial for ensuring the safety and reliability of structures. Based on different diagnostic objectives, the diagnostic methods can be classified into four levels: determining the existence of damage, locating damage, determining the extent of damage, and evaluating the remaining service life of structures. This article provides a summary of the application of modal parameters in vibration structural damage diagnosis. The research progress in using modal parameters such as modal frequency, modal shape, strain modal, curvature modal, modal strain energy and other related methods for diagnosing structural damage is reviewed. The advantages and disadvantages of these methods are discussed, and various methods are compared using numerical simulations to assess their effectiveness in diagnosing structural damage. The research results indicate that modal frequencies and displacement mode shapes are not effective in identifying the location and extent of structural damage. The strain mode method shows better performance in damage identification. The damage identification method based on the modal strain energy change of the strain modes can quantitatively determine the degree of damage and the location of damage.