A noise-robust damage indicator for characterizing singularity of mode shapes for incipient delamination identification in CFRP laminates. (15th April 2019)

• Record Type: Journal Article
• Authors: Xu, Wei; Fang, Hongyuan; Cao, Maosen; Zhou, Limin; Wang, Quan; Ostachowicz, Wiesław
• Is Part Of: Mechanical systems and signal processing. Volume 121(2019)
• Page Start: 183
• Page End: 200
• Publication Date: 2019-04-15
• Subjects: CFRP laminate -- Incipient delamination identification -- Mode shape -- Damage indicator -- 2D multi-resolution modal Teager-Kaiser energy -- Scanning laser vibrometer; Structural dynamics -- Periodicals; Vibration -- Periodicals; Constructions -- Dynamique -- Périodiques; Vibration -- Périodiques; Structural dynamics; Vibration; Periodicals; 621
• DOI: 10.1016/j.ymssp.2018.10.025
• Languages: English
• ISSNs: 0888-3270

Abstract

Highlights: 2D modal Teager-Kaiser energy can reveal singularity of mode shapes. Noise robustness is enhanced in 2D multi-resolution modal Teager-Kaiser energy. A noise-robust damage indicator is formulated for damage identification. The damage indicator is experimentally validated by non-contact laser measurement. Abstract: Identification of delaminations in the early stage is crucial to ensure the safety of CFRP laminates. In the modal domain, high spatial sampling resolution of a mode shape is required for precise location of incipient delamination. Non-contact measurement relying on laser scanning technology allows measured mode shapes to be densely sampled. Unfortunately, noise components usually contaminate such densely-sampled mode shapes, easily causing intense noise interference that likely masks actual delamination features. To address this issue, a noise-robust damage indicator is formulated for designating the presence and location of incipient delamination in CFRP laminates under noisy environments. This damage indicator is created by introducing a 2D multi-resolution modal Teager-Kaiser energy for characterizing delamination-caused singularity of mode shapes. Proof of concept of the damage indicator is numerically undertaken in finite-element CFRP laminates with incipient delaminations, with emphasis on sensitivity to damage as well as robustness against noise. The applicability of the damage indicator is experimentally validated on a CFRP laminate with an incipient delamination, mode shapes of which are precisely acquired via the non-contact measurement using a scanning laser vibrometer. The numerical and experimental results show that the damage indicator can effectively identify the presence and location of incipient delamination in CFRP laminates under noisy environments.