Efficient numerical model for the damage detection of large scale structure

A structural modeling methodology is proposed, based on the concept of Damage-Detection-Orientated-Modeling, in which a super-element representing a segment of a large-scale structure, e.g. a bridge deck, is developed. Each individual structural component is represented by a sub-element in the model. The large number of degrees-of-freedom in the analytical model is reduced, while the modal sensitivity relationship of the structural model to small physical changes is retained at the sub-element level. These properties are significant to structural damage assessment. The concept of a generic sub-element is introduced in the parameter selection strategy for model updating, and the initial finite super-element model of the structure is updated using the eigensensitivity method. Numerical studies are presented to illustrate the super-element model and model updating method. Modal frequencies and the mode shapes of the updated analytical models agree fairly well with the simulated measurements with or without noise and using incomplete measurements with a maximum error of 12%.