New materials and lightweight construction strategies are needed in the course of electrifying the drive train of automobiles. Especially the crash safety of the accumulator box is a major challenge. Fiber-metal-laminates (FML) have high-energy absorption and shield sensitive components from electromagnetic radiation through their integrated metal layers in a very compact package. The recyclability of lightweight composites is also an increasingly important topic. For these reasons, an FML with a reactive thermoplastic matrix was developed, which can also be manufactured in complex shapes . The here discussed FML consists of 1 mm DC04 metal sheets and a varying number of glass fiber interlayers.
In this paper, the mechanical properties and the damage behavior of this material is investigated on samples out of plates. The plates are manufactured in two different processes (wet compression molding and thermoplastic resin transfer molding) adjusting three fiber volume contents. Then, tensile tests are performed applying digital image correlation for strain measurement. Strain is measured in thickness direction of the specimens to detect discontinuities in the lateral strain, indicating delaminations between the layers. The influence of the fiber orientation, the production process and the fiber volume content on the yield strength, the ultimate tensile strength, the Young’s modulus and the beginning of the delamination of the interface between metal and glass fiber composite is investigated. The FMLs yield strength depends on the yield strength of the metal and the ultimate tensile strength depends on the glass fiber composite and its fiber orientation. Specimens with a ± 45° fiber orientation show higher fracture strains compared to specimens with 0° and 90° fiber orientation. The elongation of the specimen during the first delamination depends on the load distribution between the FML components.