Instantaneous wave number based structural damage detection

A method based on instantaneous wave number is proposed for structural damage detection, which is designated to describe the change of structural dynamic properties with time caused by damage. Based on the wave theory, the derivation of wave number is introduced first. Then, the method for modal parameter identification and instantaneous wave number calculation using time-varying vector autoregressive moving average (VARMA) model is depicted. Finally, the instantaneous wave number is used as the index to identify the damage of structures. Analysis results of an actual structure show that the occurrence and developing process of structural damages can be precisely identified using this index, as well, the severity of damage can be indicated exactly by spikes of instantaneous wave number.