Prediction of stress distribution and stiffness degradation in fiber metal laminates containing matrix cracking

Fiber metal laminates (FMLs) are hybrid composite materials in which several thin metal sheets and composite layers are joined. The aim of the present study was to provide an appropriate analytical method to predict damages, including matrix cracks in composite layers and plasticity in metal layers subject to static uniaxial loading. Using the proposed model, the stress distribution in the metal and composite layers in the unit cell enclosed between the two cracks was extracted. Effects of crack spacing, applied stress, and layer thickness on the stress distribution and plasticity of the metal layer were further investigated. Finally, the stiffness reduction due to damage and the energy release rate due to matrix cracking were also extracted. In order to validate the damage model, numerical simulations were performed and the results were in good agreement with the outputs of an analytical model.