An improved damage detection method based on the concept of Element Modal Strain Damage Index is introduced.
The proposed methods attempts to address some of the weaknesses of the damage detection method based on modal
curvatures. The use of numerical differentiation procedures is identified as the main cause for the poor performance of the
modal curvature method under sparse and noisy measurement. An improved damage index that does not rely on numerical
differentiation is then formulated. The proposed damage index can be calculated using only modal displacement and
modal rotation. A penalty-based minimization approach is then used to find the unknown modal rotation using sparse and
noisy modal displacement measurement. Numerical simulation and experiment validation confirm the relative advantage
of the proposed method compared with modal curvature-based approaches.
r 2007 Elsevier Ltd. All rights reserved
Received 16 April 2006
; received in revised form 12 November 2006