Damage detection in bio-polyamide 11/woven basalt fibres composite laminates subjected to dynamic events

The complexity of the damage behavior of composite materials due to the simultaneous evolution of different mechanisms involving matrixes, reinforcements and interfaces is a topic which, despite decades of knowledge, still requires specific insights and is the subject of a multitude of researches. Recently, with the attention increasingly directed towards biobased raw materials, these aspects have shown a renewed interest, prompting the need for further contributions. In this context, this experimental research work aims to investigate the damage behavior of laminate structures based on a commercial polyamide obtained from castor oil, reinforced with woven basalt fibers. The focus was on samples obtained by hot compaction using two different pressure profiles and subjected to low velocity impacts with different impact energies. Damage analysis was performed on impacted specimens using ultrasonic phased array inspections and pulsed thermography. The non-destructive analysis supported low velocity impact test results, confirming the different contribution of the damage mechanisms involved, as expected from the different level of compaction of the materials, in turn due to diverse manufacturing conditions. This research has emphasized the complementarity and effectiveness of these two non-destructive characterization techniques, providing potentially useable results for the optimal design and manufacturing of biocomposite systems.