© Fraunhofer IPA

In short

In the joint project HigHKo, a prototype of a highly integrative rear end of a battery-powered electric vehicle, consisting mainly of the components battery system, chassis, and body, was constructed. Thanks to new conceptual approaches, the application of new material and joining technologies and high functional integration, significant weight reductions could be achieved over a state-of-the-art rear end.

In detail

Innovative vehicle concepts are increasingly focusing on multi-material design. This is because the composite or hybrid system allows different materials to be combined in a single component to suit the respective stresses and functions and also offers enormous potential for reducing the mass of the component. However, the numerous advantages of using a mix of materials are offset by considerable challenges; joining different types of material poses a particular problem. As far as joining technologies are concerned, the priority is to ensure that the advantages of multi-material design are not offset by unfavorable consequences of inadequate joining processes, such as added weight or a decrease in inherent strength and stiffness at the join. The choice and use of appropriate joining methods is therefore essential to ensure that the specific material properties can be fully exploited.

In the HigHKo project, Fraunhofer IPA therefore placed a special focus on joining technologies for multi-material systems. Appropriate concepts, methods and procedures were developed. These include the JoinIT methodology for choosing suitable joining techniques for multi-material systems, an evaluation matrix for determining the lightweight design of joining technologies, or adaptation of the existing interface and risk matrix to the use case of hybrid components. In addition, failure mode and effect analyses were performed with a view to the preventive avoidance of failures in the prototypical production process, and appropriate measuring and testing equipment was selected for the joining sites.

Project partners

Dr. Ing. h.c. F. Porsche AG, ElringKlinger AG, Fraunhofer IPA


The joint project HigHKo - Hochintegratives Hinterwagen-Konzept (highly integrative rear end vehicle concept) was funded by the German Federal Ministry of Economic Affairs and Energy (BMWi) as part of the “Neue Fahrzeug- und Systemtechnologien” (new vehicle and system technologies) funding program and supervised by the project management agency for mobility and transport technologies (TÜV Rheinland). The consortium partners would like to thank BMWi for funding the project and the project management agency for its support.

© BMWi