Inline monitoring of basalt-based composites under impact tests

Scope of the present work is to visualize with infrared thermography the impact damaging of basalt-based composites. Two types of specimens are prepared with basalt fibres embedded in a polypropylene (PP) matrix, which is used either pure, or modified with the addition of a coupling agent. The latter improves the fibre/matrix interface strength providing in practice a material of different characteristics. Specimens are impacted at low velocity/energy with a modified Charpy pendulum while the infrared camera views the surface opposite to the impacted one and records thermal images in time sequence. The acquired sequences are post-processed to obtain information which may be exploited for the material characterization. In particular, the attention is to identify initiation and propagation of the impact damage and the overall delamination extension, as well as to discriminate likely differences between grafted and un-grafted composites in their impact-reaction. As a main result, the effects of the specimen's fixture on the damage extension are highlighted.