Improved Damage Location Accuracy Using Strain Energy-Based Mode Selection Criteria

Abstract

Amethod is presented forselecting thesubsetofidenti® edstructural vibration modesto beusedin® niteelement model correlation for structural damagedetection. Themethod is based on a ranking of themodesusing measured modal strain energy and is a function of only the measured modal parameters. It is shown that a mode selection strategy based on maximum modal strain energy produces more accurate update results than a strategy based on minimum frequency. Strategies that use the strain energy stored by modes in both the undamaged and damaged structuralcon® gurationareconsidered.Itisdemonstratedthatmoreaccurateresultsareobtainedwhen themodes are selected using the maximum strain energy stored in the damaged structural con® guration. The mode selection techniques are applied to the results of a damage detection experiment on a suspended truss structure that has a large amount of localized modal behavior.