Damage assessment from earthquake records

ABSTRACT The correlation between the variation of the fundamental period of vibration of a structure during an earthquake and the damage that the structure undergoes is investigated. The variation of the fundamental period can give qualitative and quantitative information for the detection and the assessment of damage during earthquakes. A time varying model of the structure, based on modal analysis, is used. The parameters are estimated using maximum likelihood techniques. Several buildings, with different degrees of damage, are examined.