On the delamination self-sensing function of Z-pinned composite laminates. (18th May 2016)

• Record Type: Journal Article
• Authors: Zhang, B.; Allegri, G.; Yasaee, M.; Hallett, S.R.; Partridge, I.K.
• Is Part Of: Composites science and technology. Volume 128(2016)
• Page Start: 138
• Page End: 146
• Publication Date: 2016-05-18
• Subjects: Structural composites -- Smart materials -- Delamination -- Z-pinning; Composite materials -- Periodicals; Composite materials; Fibrous composites; Periodicals; 620.118
• DOI: 10.1016/j.compscitech.2016.03.019
• Languages: English
• ISSNs: 0266-3538

Abstract

Abstract: This paper investigates for the first time the usage of through-thickness reinforcement for delamination detection in self-sensing composite laminates. Electrically conductive T300/BMI Z-pins are considered in this study. The through-thickness electrical resistance is measured as the delamination self-sensing variable, both for conductive and non-conductive laminates. The Z-pin ends are connected to a resistance measurement circuit via electrodes arranged on the surface of the laminate. The delamination self-sensing function enabled by conductive Z-pins is characterised for Mode I/II delamination bridging, using single Z-pin coupons. Experiment results show that, if the through-thickness reinforced laminate is electrically conductive, the whole Z-pin pull-out process associated with delamination bridging can be monitored. However, for a non-conductive laminate, delamination bridging may not be sensed after the Z-pin is pulled out from one of the surface electrodes. Regardless of the electrical properties of the reinforced laminate, the through-thickness electrical resistance is capable of detecting Mode II bridging, albeit there exists an initial "blind spot" at relatively small lateral deformation. However, the Z-pin rupture can be clearly detected as an abrupt resistance increase. This study paves the way for exploring multi-functional applications of through-thickness reinforcement.