A new flexibility-based damage index for structural damage detection

摘要

A new flexibility-based damage index has been proposed for structural damage detection. It is derived from the strain energy theory that the ratio of the flexural stiffness of the structure before and after damage is a function of the uniform load surface (ULS) curvature. The novelties of the proposed damage index lie in the following aspects: (1) the proposed method directly uses the deflection which is predicted from an advanced signal processing procedure, while the modal shape is approximately used to replace the deflection in the strain energy calculation for damage detection in the literature; (2) the scaling factor calculated during flexibility identification is used to weight each mode for damage detection, unlike the damage index in the literature equally weighting all modes for structural damage detection. Examples of a 12-story building model and a T-beam bridge model illustrate that the proposed damage index successfully detects structural damage locations in both the single- and multiple-damage cases.