A simple and robust approach for visual overload indication - UD thin-ply hybrid composite sensors

Abstract

A novel, purpose-designed, thin interlayer glass/carbon-epoxy hybrid composite sensor concept is presented here that can be used for structural health monitoring (SHM), offering potential for safer operation in service. The hybrid composite sensors indicate the overload of a structure by exhibiting a change in their appearance when loaded in tension over a predefined strain value. The sensors can be attached to a component either as a structural sensing layer or integrated locally as demonstrated in this study through real-life applications. Furthermore, various test methods have been utilised to characterise the bonded-on sensors including mechanical testing, Digital Image Correlation (DIC) and Acoustic Emission (AE) measurements. An optimal configuration has been identified with the utilised materials that 2 can potentially be used in applications such as sporting goods, civil engineering structures (e.g. truss and bridge elements) as well as pressure vessels.

Effect of Plasma-Treatment of Interleaved Thermoplastic Films on Delamination in Interlayer Fibre Hybrid Composite Laminates

“…The delamination produced light zones well visible from the outer surfaces of the specimens in contrast to the darker undamaged parts (see damage sequence in Figure 6). This feature is due to the translucency of the glass/epoxy plies and it was already observed in other studies on carbon/glass-epoxy hybrid composites [50,51].…”

“…The delamination produced light zones well visible from the outer surfaces of the specimens in contrast to the darker undamaged parts (see damage sequence in Figure 6). This feature is due to the translucency of the glass/epoxy plies and it was already observed in other studies on carbon/glassepoxy hybrid composites [50,51]. A large carbon-carbon peak at 284.8 eV was observed, which was a result of the overlapping peaks of C-C and C=C bonds and a feature at +1.67 eV (286.4 eV) caused by an overlap of the C≡N of the polymer and possibly a small amount of residual C-O groups.…”

Improving the extension–twist coupling performance of practically warpage-free laminates via layup hybridization

“…carbon/epoxy–glass/epoxy hybrids). Hybridization has been shown to be advantageous in many applications, including pseudo-ductile 18 and high damping 19 laminates, shape-memory alloy composites, 20 laminates with built-in overload sensors 21 or adaptive multistable structures with advanced mechanical performance. 22 The advanced behaviour of the hybrid laminate results from the complex effects of combining plies with different mechanical, thermal, etc.…”