Nonlinear behaviour of glass fibre reinforced composites with delamination

The aim is to assess the nonlinear behaviour of glass fibre composite having controlled delaminations. The experimental analysis focused on the variation of nonlinear parameters as function of delamination size. Through a set of increasing resonance amplitudes applied on a delaminated glass fibre reinforced composite, the frequency shift and the specific damping coefficient shift were evaluated as a function of strain amplitude. The nonlinear elastic and dissipative parameters related respectively to the frequency and damping, were determined for different bending modes and different delamination lengths. These parameters were compared with the linear vibration parameter. The results show that nonlinear parameters are more sensitive to the presence of delamination in composite.