Damage detection in circular cylindrical shells using active thermography and 2-D discrete wavelet analysis. (March 2019)

• Record Type: Journal Article
• Authors: Mahdian Parrany, Ahmad
• Is Part Of: Thin-walled structures. Volume 136(2019)
• Page Start: 34
• Page End: 49
• Publication Date: 2019-03
• Subjects: Circular cylindrical shells -- Non-destructive testing -- Active thermography -- 2-D discrete wavelet analysis -- Squared residual damage index; Thin-walled structures -- Periodicals; 690.1
• DOI: 10.1016/j.tws.2018.12.028
• Languages: English
• ISSNs: 0263-8231

Abstract

Abstract: In this paper, the ability of the active thermography as a non-destructive testing technique to detect internal damages in circular cylindrical shells is investigated. The transient heat transfer problem of the damaged structure is analyzed using the ABAQUS numerical modeling software. To reveal the defects more clearly, thermal data are enhanced using the two dimensional discrete wavelet transform as a post-processing technique. The effect of various damage parameters, including damage depth and orientation is studied. Meanwhile, a damage index based on the squared residual of the wavelet coefficients is proposed and its performance is examined. Finally, experimental studies are illustrated to confirm the efficacy of the proposed method and its applicability for structural diagnostics. Graphical abstract: Highlights: Damage detection in circular cylindrical shells using active thermography is studied. Thermal images are processed by 2-D discrete wavelet transform. Cylindrical shells with damages of different depths and orientations are tested. A damage indicator based on the squared residual of wavelet coefficients is proposed. Experimental studies are presented to confirm the efficacy of the proposed method.