The production of a car is energy and resource intensive. With a higher mileage of the vehicles, the continuous energy demand in production could be significantly reduced and the extraction of mineral resources significantly reduced. This is where the KOSEL research project comes in, for which the Chemnitz Fraunhofer Institute for Machine Tools and Forming Technology IWU has joined forces with partners (EDAG Engineering Group, INVENT GmbH, Röchling EP, BSMRG GmbH, Emden-Leer University of Applied Sciences and TU Dresden) from industry and research.

Lightweight e-commercial vehicles from the construction kit

In the KOSEL project, the project team has created the basic concept for a light e-utility vehicle with a gross vehicle weight of 3.5 tonnes, whose components are entirely modular. The three main modules, front end, battery box and rear end, are connected to each other via fixed interfaces, so that replacement is possible with very little effort. The e-vehicle platform has been designed and prototyped for a service life of up to 30 years and a mileage of up to one million kilometres in changing application scenarios.

Sustainable material concept

The material concept envisages the use of durable materials primarily in the highly stressed areas that are intended for multiple reuse. According to Fraunhofer IWU, carbon fibre reinforced plastics (CFRP) are best suited for this purpose. Due to its long-term usability, carbon fibre-reinforced plastic is primarily intended for use in the area of sills.

Innovative sills thanks to auxetic structures

For this neuralgic area, the concept of a new type of sill was also developed, which is better designed for an oblique impact. This is based on a specific crash principle: the inversion of CFRP crash tubes, their special orientation within the sill and the introduction of force via auxetic structures. These structures have the unusual property of contracting transversely to the direction of compression. The intact CFRP crash tubes can also be reused in new vehicle models or generations after an accident or at the end of a vehicle's service life - either 1:1 or after being cut to size elsewhere, for example in the rear section.

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