Sequential eigen-assignment technique for structural damage identification

Abstract

This research proposed an eigen-assignment technique for locating and identifying structural damages using an incomplete measurement set. The sequential method is computationally efficient and requires no sensitivity calculations. Established by the finite element method, the mass and stiffness matrices are partitioned and measured partial eigenvectors are expanded to full modes. By matching calculated eigen-pairs with their measured counterparts as the termination criterion, the procedure solves for the stiffness reduction coefficients sequentially using a nonnegative least-squares solution scheme. The proposed approach can still find the damaged locations and the extent of the damage in a structure with much less measured degrees of freedom and even less measured modes than the finite element analysis degrees of freedom. The effectiveness of the technique is demonstrated by solving two cases based on a structure built for a benchmark study by the Group for Aeronautical Research and Technology in Europe (GARTEUR SM-AG19 structure)