Polarization-resolved terahertz imaging of intra- and inter-laminar damages in hybrid fiber-reinforced composite laminate subject to low-velocity impact

• Published in: Composites. Part B, Engineering Vol. 92; pp. 167 - 174
• Main Authors: Dong, Junliang, Locquet, Alexandre, Declercq, Nico F., Citrin, D.S.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.05.2016; Elsevier
• Subjects: A. Hybrid; A. Polymer-matrix composites (PMCs); B. Impact behaviour; Bioengineering; Biomaterials; Carbon fiber reinforced plastics; D. Non-destructive testing; Damage; Engineering Sciences; Fiber composites; Fittings; Glass; Imaging; Laminates; Life Sciences; Terahertz imaging; Three dimensional; A. Polymer-matrix composites (PMCs); Terahertz imaging; B. Impact behaviour; A. Hybrid; D. Non-destructive testing; Impact behaviour Terahertz imaging; Non-destructive testing A; D; Hybrid A; Polymer-matrix composites (PMCs) B
• ISSN: 1359-8368; 1879-1069
• DOI: 10.1016/j.compositesb.2016.02.016

Terahertz imaging is applied to characterize a hybrid fiber-reinforced composite laminate subject to low-velocity impact in this study. The hybrid fiber-reinforced composite laminate comprises unidirectional glass/epoxy and carbon/epoxy plies with a cross-ply stack pattern. Both impact-induced intra- and inter-laminar damages are successfully detected, and the damage evolution throughout the thickness is also evaluated. The interaction between the terahertz polarization and carbon-fiber orientation is investigated in detail. Inter-laminar damage at the interface and the intra-laminar damage close to the same interface can be differentiated via polarization-resolved imaging. With a parameter fitting method based on multiple regression analysis, delamination is characterized quantitatively. Terahertz C- and B-scan images clearly exhibit the propagation of the damage from the top to the bottom surface in three dimensions.