Study of Damage Tolerance in Double-Double Glass/Epoxy Composites under Low-Velocity Impact
Double-double laminate; GFRP; CAI; LVI
In structural applications using GFRP composite materials, the double-double (DD) is a new class of non-conventional laminates, characterized by a simplified stacking sequence with two pairs of plies, denoted as . The DD concept, developed in 2017, has shown potential to replace conventional quasi-isotropic quadraxial laminates (Quad) due to its ability to reduce weight, optimize design, simplify manufacturing processes, and lower costs. Although the DD concept has been attracting increasing interest within the scientific community, experimental data remain scarce for different materials and loading conditions, particularly in structural applications such as wind turbine blades. In this context, the present study aims to compare the performance of two equivalent GFRP glass/epoxy laminates: Quad ([±45/(0/90)3]s) e DD ([±15/±75]4T), through uniaxial compression tests, low-velocity impact (LVI), and compression after impact (CAI) tests at four nominal energy levels (30, 45, 60, and 74 J). The results demonstrate that replacing the quadraxial laminate with the double-double configuration, within the parameters investigated in this study, is feasible while maintaining mechanical performance, thereby highlighting its potential for application in the wind energy industry.