IMPACT DAMAGE RESISTANCE OF VARIOUS FIBER METAL LAMINATES

The impact damage resistance of Fibre Metal Laminates (FML) is studied . FML is a new family of laminated materials which consist of thin alu minium layers bonded together by intermediate fibre/epoxy layers. Diff erent glass fibre FML variants are compared with Al 2024-T3, and carbo n/PEI composites. The effect of the relative glass/epoxy content in FM L is determined. FML shows an equal to 15% better minimum cracking ene rgy at low velocity impact compared to monolithic aluminium, but behav es much better (2-3.5x higher minimum cracking energy) at high velocit ies. The impact damage resistance of FML increases with an increasing glass/epoxy content. This is partly due to the strain rate sensitivity of the glass fibres. FML are also superior because during impact dela mination occurs, and the laminae consequently will be loaded in a more efficient membrane deformation compared to the dominant bending defor mation of the monolithic material. Carbon/PEI thermoplastic composites have a poor impact damage resistance.