Nonlinear multiple breathing cracks detection using direct zeros estimation of higher-order frequency response function

On-board structures are currently submitted to high-level vibrations which may affect their integrity and operational lifetime. Structural health monitoring is then of great interest to avoid mechanical failures and to increase operational safety of mechanical systems. Indeed, in the case of cracked structures, the presence of cracks may affect the dynamic behavior. Thus, this paper focusses particularly on the detection and location of small cracks using the nonlinear response of cracked structures and more specifically using the zeros of the Higher-Order Frequency Response Function. The proposed method is based on the Direct Zeros Estimation algorithm to identify the antiresonances of the system. The locus of the identified antiresonances according to the crack location are discussed through numerical examples applied to the simplified nonlinear finite element model of a rectangular beam with multiple breathing cracks. (C) 2020 Elsevier B.V. All rights reserved.