This dataset contains data showing the effect of interlocked thin-ply reinforcement units on the fracture toughness and compression after impact strength of CFRP laminates. For both the fracture toughness and the CAI experiments, tests were conducted on non-reinforced baseline specimens, as well as reinforced specimens. These experiments were conducted to test a reinforcement concept, consisting of creating reinforcement units by interlocking two thin-ply prepreg layers with a tab-and-slit geometry. These reinforcement units are then inserted between the plies of a regular composite lay-up. This reinforcement concept was first presented at the 18th European Conference on Composite Materials (2018, Athens, Greece). More information on the concept can be found at: http://wwwf.imperial.ac.uk/aeronautics/research/pinholab/interlock-tabs/. The fracture toughness section of this dataset contains both mode I and mode II data. The mode I data was acquired using DCB specimens, and the mode II data was obtained from 4-point end notch flexure tests. Force, displacement, crack length, and strain energy release rate during the test are provided for all specimens. The CAI section of the dataset contains post-impact C-scans, as well as force, displacement, and strain gauge data from the subsequent compression tests.

The authors are grateful for the funding received from the EPSRC under grant number EP/M002500/1. S. Pimenta acknowledges the royal Academy of Engineering for her Research Fellowship on "Multiscale discontinuous composites for large scale and sustainable structural applications" (2015-2019).