Damage evaluation of an axially loaded beam using modal flexibility

Abstract

This work proposes a new nondestructive damage evaluation method that can detect, locate, and size damage by utilizing dynamically measured modal flexibility. The proposed method is particularly useful for a slender beam under an axial force. It belongs to the response-based approach because the response data are directly related to damage without the use of a numerical model. An equation governing the damage-mechanism is theoretically derived from modal flexibility. Solving the set of resulting equations provides the evaluation of damage. The accuracy of the proposed method is verified using a set of numerical simulatio ns. The proposed method attempts to resolve the mode selection problem, the singularity problem, the axial force problem, and the absolute severity estimation problem, all of which exist in earlier attempts. The proposed method is capable of conducting deta iled local inspections using incomplete measured modal parameters of a selected class of structures.