This publication describes new process chain approaches for the manufacturing of intrinsic hybrid composites for lightweight structures. The introduced process chains show a variety of different part and sample types, like insert technology for fastening of hollow hybrid shafts and profiles. Another field of research are hybrid laminates with different layers of carbon fiber reinforced plastics stacked with aluminum or steel sheets. The derived process chains base on automated fiber placement, resin transfer molding, deep drawing, rotational molding and integral tube blow molding.

In this study a numerical simulation model was designed for representing the joining process of carbon fiber-reinforced plastics (CFRP) and aluminum alloy with semi-tubular self-piercing rivet. The first step towards this goal is to analyze the piercing process of CFRP numerical and experimental. Thereby the essential process parameters, tool geometries and material characteristics are determined and in finite element model represented. Subsequently the finite element model will be verified and calibrated by experimental studies. The next step is the integration of the calibrated model parameters from the piercing process in the extensive simulation model of self-piercing rivet process. The comparison between the measured and computed values, e.g. process parameters and the geometrical connection characteristics, shows the reached quality of the process model. The presented method provides an experimental reliable characterization of the damage of the composite material and an evaluation of the connection performances, regarding the anisotropic property of CFRP.

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Manufacturing of complex tubular workpieces often requires medium‐based forming processes. Because of the inaccessibility to the inside of the parts, joining of attached parts and part handling are difficult. Loss of accuracy during thermal joining is another disadvantage. A new method of spot‐joining by forming is a combination of hydroforming and clinching or hydroforming and self‐pierce riveting. In contrast to the standard method the clinching or self‐pierce riveting is done without die. A high pressure fluid undertakes the task of the die during joining. This die‐less procedure also extends the range of applications to areas which are not covered by standard techniques. By integrating joining into the hydroforming process, assembly processes can be shortened. In order to exploit velocity dependent material properties, for example increase in formability and decrease of spring back, self‐pierce riveting during the hydroforming process by means of impulse load has also been researched among other conventional quasi‐static force transmissions. Numeric simulations were used for the theoretical description of the procedure. One goal of the simulations is the characterisation of the most influential parameters on the process as a function of the material properties, tool kinematics/‐geometry and of the friction conditions. The simulation results permit not only the characterisation of the process, but also the theoretical predetermination of optimal joining parameters for various material and geometry combinations with fewer experiments.

Lightweight design for automotive applications gains more and more importance for future products, independent from the powertrain concept. One of the key issues in lightweight design is to utilize the right material for the right application using the right value at the right place. This results irrevocably in a multi-material design. In order to increase the efficiency in manufacturing car components, the number of single parts in a component is decreased by increasing the complexity. Examples for the state of the art are tailored welded blanks in cold forming, tailored tempering in press hardening or metallic inlays in injection molding of polymers. The challenge for future production scenarios of multi-material components is to combine existing technologies for metal- and polymer-based applications in efficient hybrid process chains. This paper shows initial approaches of hybrid process chains for efficient manufacturing of hybrid metal-polymer components. These concepts are feasible for flat as well as for tubular applications. Beside the creation of the final geometric properties of the component by a forming process, integrated joining operations are increasingly required for the efficiency of the production process and the performance characteristics of the final component. Main target of this production philosophy is to create 100% ready-to-install components. This is shown in three examples for hybrid process combinations. The first example deals with the combination of metal forming and injection molding of polymers. Example number two is the application of hybrid metal-polymer blanks. Finally, example number three shows the advantages of process integrated forming and joining of single basic components.