Efficient lightweight construction for crash-relevant structural parts based on intrinsic hybridization: Presentation held at 4th International Conference Hybrid Materials and Structures, 29th April 2020, Karlsruhe

Compared to monolithic constructions, hybrid structures have properties that are more beneficial. For example, parts, which are made of a combination of a fiber rein-forced polymer (FRP) and a ductile metal, can bear high operation loads on the one hand. On the other hand, the resulting parts show high energy dissipation rates within crashes. Nevertheless, the mass of the parts is still low. One main requirement for the utilization of these hybrid parts within large-scale production is the availability of efficient manufacturing processes. This contribution deals with the development of hybrid composite parts optimized for crash applications. The manufacturing of these hybrid parts is realized with a novel intrinsic process approach. According to this process approach, the generation of the part’s geometry as well as the hybridization are realized in a single manufacturing step. The mechanical properties of the hybrid part strongly depends on the resulting inter-face between its components. By the use of a combination of mechanical form fit and adhesive bonding, the interface performance shall significantly be improved. An additional surface coating based on organically modified silicates on the metallic insert works as an adhesive promoter between the thermoplastic matrix of the FRP and the metal as well as a corrosion barrier. The form fit is generated during the part manufacturing process itself. Therefor an innovative metallic insert is designed. Due to its geometry, out-of-plane deformations are induced by a tension force and result in the generation of form fit elements. During the global forming process, these form fit elements penetrate the molten polymer and the form fit arises. Aiming for an efficient dimensioning process, the mechanical behavior of the parts is modelled and simulated having regard to the manufacturing history. To capture the properties of the applied components, nonlinear material models at large strains are developed based on directly connected rheological elements. Moreover, the complex inner and outer geometry, which is influenced by the manufacturing process, is taken into account by simulating sub steps of the fabrication process. Consequently, requirements on the process control can be conducted from finite element simulations with varied process parameters. Additionally, the rate-dependent deformation behavior of the hybrid composite is experimentally investigated. To this end, a specimen geometry is developed to especially characterize the interface between the FRP and the metal. Having the application of the hybrid composite in mind, a Split-Hopkinson pressure bar is therewith applied for the high dynamic testing. Consequently, the bundling of expertise in the field of production, mechanics and materials technology enables the development of an intrinsic hybrid composite for crash-relevant structural parts, which is efficiently fabricated in a one-step process