Interlaminar mechanical properties of nano- and short-aramid fiber reinforced glass fiber-aluminum laminates: a comparative study

Delamination damages limit the application potential of Fiber metal laminates, hence improving the interlaminar mechanical properties has always been a research focus and challenge in this field. The toughening effect of two fillers, i.e., nano-aramid fibers (ANFs) and short-aramid fibers (ASFs), which are used at the interface of glass fiber-aluminum laminates, have been investigated. Chemical pretreatments of aluminum alloy surface were conducted to ensure the better adherence between the fiber composites and metal sheets. Results revealed that Mode-I and Mode-II fracture toughness of the laminates could be simultaneously improved when using the two fillers at the interface of glass fiber-aluminum laminates. Attributed to the better dispersion of ANFs in epoxy matrix, the toughening performance of ANFs is better than that of ASFs in this case. The mechanism of interlaminar toughening was revealed with electron microscopic observation of fracture morphology. Meanwhile, the finite element analysis based on bilinear cohesive zone model was adopted to predict the increased interlaminar tensile and shear strength.

Automated summary

The study found that using two fillers at the interface of glass fiber-aluminum laminates can simultaneously improve the Mode-I and Mode-II fracture toughness of the laminates. Due to the better dispersion of nano-aramid fibers in the epoxy matrix, their toughening performance is better than that of short-aramid fibers in this case.