Effects of moisture on the frequencies of vibration of woven fibre composite doubly curved panels with strip delaminations

• Natural frequencies of woven fibre composite panels are calculated.
• The moisture effects and strip delaminations are considered in the analysis.
• Natural frequencies are observed with different boundary conditions.
• Frequency reduction is marked with increase in moisture content and delamination size.
• The reductions of frequencies are due to the changes in stiffnesses of laminates.

The present study deals with the effects of moist environment on the natural frequencies of vibration of Glass/Epoxy woven fibre composite doubly curved panels with strip delamination using the finite element method (FEM). For modelling the delamination, multipoint constraint algorithm is incorporated in the analysis. The effects of boundary condition, delamination size and shape of panels on natural frequencies of vibration are investigated in the moisture content range. The frequencies of vibration reduce with increase of moisture in delaminated curved panels. The reductions of frequencies are more prominent for higher degree of moisture concentrations and significantly affected by boundary conditions.