Reduction of slamming damage in the hull of high-speed crafts manufactured from composite materials using viscoelastic layers

For high-speed crafts, the shift to new materials was initially driven by a need to obtain lighter, stronger vessels, with complex geometries and adapting the mechanical properties of the material to the needs of the design. A new experimental set-up has been designed to reproduce the slamming impacts in small samples of the material, at different velocities and impact energies. Ultrasonic C-scan inspection of each of the prepared specimens has been conducted to evaluate its quality level and the absence of porosity zones. After a certain number of cycles of impacts, each panel was removed and inspected again to assess damage evolution, and the micromechanisms of interlaminar and intralaminar damage propagation. Damage levels have been correlated to residual strengths using AITM-0010 test method for determination of compression strength after impact. It is shown how is possible to effectively mitigate the damage by slamming by inserting a viscoelastic layer into the GFRP panels. The structured combination of a polymer with high deformation capacity with domains of a second, rigid polymer, dampens the impacts and delays the damage progression, improving the dissipation of impact energy, thus protecting the structure of the hull and increasing the service life of the high-speed crafts.