A study on tensile properties of a novel fiber/metal laminates

Fiber metal laminates (FMLs) are layered materials based on stacked arrangements of aluminum alloy layers and fiber reinforced plastic (FRP) layers. FMLs have benefits over both aluminum and fiber reinforced composites. In this work, glass fibers and Kevlar fibers are used together and effect of fibers orientation on tensile behavior of this novel material is investigated. A modified classical laminate theory (CLT), which considers the elastic–plastic behavior of the aluminum sheets, and a numerical simulation method based on finite element modeling (FEM) are used to predict the stress–strain response of FMLs. Specimens were made and mechanical testing was performed to determine in-plane tensile properties of this type of FMLs. Good agreement is obtained between the models predictions and experimental results. Test results show that fiber sheets with zero orientation in laminate improve modulus of elasticity, yield stress and ultimate tensile stress considerably. Statistical analysis of data is done and an estimated response surface of ultimate tensile strength of the specimens as a function of fiber orientation in each layer is obtained. Also, the effect of the independent variables and interactions with their relative significance on the tensile behavior is specified. It is shown that Kevlar fiber orientation is the most important parameter between all variables and their interactions.