Structural Damage Detection Based on Improved Sensitivity Function of Modal Flexibility and Iterative Reweighted lp Regularization.

The l 2 regularization is usually used to deal with the problems of under-determinacy and measurement noise for the conventional sensitivity-based model updating damage detection methods. However, the l 2 regularization technique often provides overly smooth solutions and thus cannot exhibit the sparsity of the structural damage due to the promotion of the 2-norm term on smoothness. In the study, a structural damage detection method is proposed based on an improved modal flexibility sensitivity function and an iterative reweighted l p (IR l p) regularization. Specifically, the sensitivity function is established by introducing changes in the mode shapes into the derivative of eigenvalue and can be applied to identify the localized damage more accurately. Additionally, IR l p regularization is proposed to deal with the ill-posed problem of damage detection in a noisy environment. The proposed IR l p regularization is compared with the l 1 and l 2 regularizations through a numerical and an experimental examples. The numerical and experimental results indicate that the IR l p regularization can more accurately locate and quantify the single and multiple damages under the noise situation. The maximum identification errors are only 5.16% and 5.67%, respectively. Moreover, compared to the basic modal flexibility sensitivity function, the improved function is more sensitive to the damage. The maximum identification error of the improved function is less than 6%, while the relative errors are significantly larger in the basic function. [ABSTRACT FROM AUTHOR]