A demand raised is how to improve the survivability of aircraft and naval structures concerning low- and high-velocity impacts. Since fundamental failure is due to mainly by fracture, a fundamental understanding of both mechanisms and mechanics of the material is crucial. It is important to understand the deformation and damage mechanisms involved in the impact to improve the design of composite structures. Several approaches have been exploited to improve the impact damage resistance of composite laminates in different conditions. Among these, the development of composite laminates stacking different fibres in the same matrix results very interestingly. This paper deals to investigate on the high and low speed impact performance of hybrid composite configurations made of glass/carbon and basalt fibres. Low-velocity impact at penetration and high speed tests at different impact velocity were carried out at the room and low temperatures to evaluate the goodness of hybridization proposed and the temperature effect on the composite performances. Among the three proposals, a hybrid basalt carbon configuration was identified as the best both at low speeds and at high impact speeds for both temperatures tested.

This work investigated the effect of repeated low-velocity impacts at different energy levels on vinyl ester composite laminates. In particular, hybrid composite laminates made by carbon woven fabric and glass woven fabric impregnated by vinyl ester resin were subjected to 1, 5 and 10 impacts for three different energy levels (U=5 J, 10 J and 20 J). The multi-impact damage evolution was studied by combining several non-destructive techniques such as Pulsed Thermography, Electronic Speckle Pattern Interferometry and Ultrasonic C-scanning. Along with images of detected damaged areas, some impact parameters such as contact force, deflection and absorbed energy were provided.

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Laminated composite structures are subjected to impact damage during maintenance and manufacturing operations and their life service. Driven by the necessity to value damage tolerance and durability of composite materials, an analysis of multi-hit impact is conducted to reproduce the real service conditions. Despite many studies in the literature investigated the properties of composites at low impact velocity, in contrast the behavior of the hybrid configuration, especially at repeated impacts, result still little known. This work presents an experimental and numerical study of the dynamic behavior at the repeated low-velocity impact of a carbon and glass fibers hybrid composite laminate.

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