Investigation of structure–flexural response relations in thermoplastic carbon/glass fiber‐metal laminates

Abstract In the current work, fiber‐metal laminates (FMLs) consisting of alternated continuous fiber‐reinforced thermoplastic composite layers and aluminum alloy sheets were proposed by the hot‐pressing method. Carbon fiber‐reinforced polyamide 6 (PA6/CF) and glass fiber‐reinforced polypropylene (PP/GF) prepregs were selected as composite layers. The effect of the assembly method between composite prepreg and aluminum sheets as well as the stacking configurations on the flexural response of FMLs were investigated. Meanwhile, the macro and micro‐structural observations were performed to characterize failure mechanisms in these structures. Experimental results revealed that the strength and stiffness of hybrid FLMs depended on the material property on the surface layer. With the stacking sequence of aluminum sandwiched by PA6/CF achieved the highest flexural strength of 535.3 MPa and modulus of 63.6 GPa in the series of FMLs, which could achieve satisfied lightweight and strength‐stiffness properties. The ductile deformation of aluminum sheets and fracturing and pulling out of the fibers were the main characterized failure mechanisms of thermoplastic FMLs. For glass fiber‐metal laminates, stacking configurations of three aluminum sheets alternation with four PP/GF intermediate layers achieved a favorable flexural property. Above all, the proposed thermoplastic FMLs have great potential in civil applications especially in the automobile industry as structural parts. Highlights Thermoplastic fiber‐metal laminates are designed and fabricated. The assembly method and stacking sequences influence the flexural property. FMLs with PA6/CF and aluminum achieve satisfied strength stiffness. PP/GF prepreg and aluminum layer display ductile deformation mode.