Dynamic 3D strain measurements with embedded micro-structured optical fiber Bragg grating sensors during impact on a CFRP coupon

Composite materials are increasingly used in aerospace applications, owing to their high strength-to-mass ratio. Such materials are nevertheless vulnerable to impact damage. It is therefore important to investigate the effects of impacts on composites. Here we embed specialty microstructured optical fiber Bragg grating based sensors inside a carbon fiber reinforced polymer, providing access to the 3D strain evolution within the composite during impact. We measured a maximum strain of -655 mu epsilon along the direction of impact, and substantially lower values in the two in-plane directions. Such in-situ characterization can trigger insight in the development of impact damage in composites.