Because of their high specific stiffness and strength, fiber reinforced plastics (FRP) are preferred lightweight materials. Recent developments show a growing industrial interest in the integration of thermoplastic FRP in complex structures for high volumes. However, there are still shortcomings for these materials concerning the insufficient energy absorption in case of failure and the limited opportunities available for the assembly with other components. Improvements in the crash performance can be achieved for instance with the selective reinforcement of the FRP structure with ductile metallic inserts. The present study shows the interlaminar shear strength and scanning electron microscope (SEM) samples of a novel load optimized hybrid composite consisting of a continuous fiber-reinforced thermoplastic matrix, in which a metal core is integrated.

Growing mechanical, economic and environmental specification lead to multi-material designs. Based on an extensive basic research, more achievements and experiences regarding the manufacturing technologies and mechanical properties of hybrid laminates were achieved in the Institute of Lightweight Structures and Polymer Technology. The present study shows the development, characterization and forming of novel hybrid laminates, made of steel sheets (HC220Y+ZE, t = 0.25 mm) and carbon fiber reinforced polymers (Polyamide 6). The interface-optimization of the hybrid laminates was carried out with two different bonding agents. The results of a three point bending test underline the potential of the innovative material. A hybrid roof crossmember was formed on a hydraulic Tryout-Press successfully.

The flow drill joining concept (FDJ) allows the load adjusted joining of continuous fiber reinforced thermoplastics (FRTP) and metallic sheets without auxiliary joining elements. As there is no scathe done to the fiber reinforcement, a radial realignment of the fibers leads to high-strength joints with high lightweight potential. In terms of their use in automotive lightweight construction, an important requirement for joining technologies is the resistance to temperature loads and chemicals, applied in the production processes, e.g., in vehicle lacquering. Therefore, force flux aligned FDJ-joints were investigated in cross tension and shear testings, after passing through a serial cathodic dip painting (CDP) process. The results show that the CDP-treatment does not adversely affect the quasi-static properties of the tested FDJ-joints, as they resist shear loads up to 2900 N and cross tension loads of about 1100 N, both, before and after the lacquering process.

Large-scale curved structures such as wind turbine wings usually require a special and cost intensive transport to the installation destination. These transport and installation costs can be reduced by a flat transport condition and the possibility of layering several structural components. For this reason, the focus at the Department of Lightweight Structures and Polymer Technology at TU Chemnitz was on a novel active material composite, which enables resource-efficient mass production and has a new component architecture. The large-volume multidimensional curvature of the active structure could be achieved by using a shape memory polymer (SMP). The associated reduction of the specific investment costs, the use of materials and the possibility of an integrative design, can contribute to the fact that, for example, the small wind turbines will become an economically viable investment in the future. The active structure influencing was represented by means of a finite element simulation (FEM) for different material composites and could be verified by generic demonstrators regarding its validity.

The manufacturing of high load components in automotive and mechanical engineering demands for an increased usage of combined plastics processing procedures. In practice, full plastic hybrid components are produced in a series of individual processes such as thermoforming or injection molding. The constructive implementation has often only material-substituting character wherein the high potential for lightweight anisotropic fiber composites is exploited only to a limited extent. Based on the application of a coupling brace in a vehicle, a new component design for function-integrated interface elements is enabled by an integrated injection molding technology. The targeted transfer of high local stresses by load-bearing insert elements regarding contoured metal sheets or Fiber Reinforced Thermoplastic Composites (TP-FRC) semi-finished products with endless fiber reinforcement enables efficient dimensioning of components. This fusion of technologies to a Multi Material Design (MMD) form the basis for novel weight-optimized, as well as cost-effective applications and lead to a high bending stiffness and high strength of structures. The composite strength of MMD components is increased by a variation and optimization of the thermoplastic/TP-FRC respectively thermoplastic/metal-interfaces. This objective will be achieved by highly efficient and integrated process flows and by the new entire construction of the component.