Low Velocity Impact Behaviour of Reinforced Plastic Laminates: Indentation and Penetration Laws validated for different Fibres and Matrices

Low velocity impact behaviour of laminates made of different reinforcements and matrices was studied in this paper. Impact tests were carried out up to penetration and at increasing energy values on glass fibre reinforced phenolic resin laminates, with different configurations (quasi-isotropic and orthotropic) and thicknesses, in order to correlate the indentation depth with the impact energy. Impact results obtained on basalt fibre reinforced epoxy resin laminates with different thicknesses were compared too. The stacking sequence of the glass fibre specimens was found to have no influence on the penetration energy but revealed lower indentation for the quasi-isotropic ones, under the same impact energy, for all the thicknesses tested. Moreover, basalt laminates showed lower indentation depths, compared to the data from this research and present in literature on other material systems. Finally, the results from the impact tests were used to validate existing semi empirical laws for the evaluation of the indentation and the penetration energy, in which the fibre content assumes the most relevant role