At the “Lightweight Tech Talk by AZL on “High-Performance SMC”, Dr Hannes Grimm-Strele from Fraunhofer ITWM,
one of ALMA consortium partners, showed how to efficiently model
the anisotropic nonlinear material behaviour using a three-scale modelling approach

SMC Composites, Fibre Orientation modelling

Excerpts from the talk:

I had the possibility to present our work on the process simulation and mechanical characterization of SMC composites in the Lightweight Tech Talk by AZL on “High-Performance SMC” on November 16, 2023. The event took place online and there were about 100 participants. Dr. Kai Fischer, Managing Partner of AZL, gave a short introduction in the event and presented the services provided by AZL. Then, Sergio Gastaldi and Guido Arcangeli from the family-owned Italian company Persico presented, besides their composite presses for SMC production, a patented method for a one-step SCM+Aluminium moulding process.

My talk was shared with the talk of Dominic Schommer from the Leibniz-Institut für Verbundwerkstoffe in Kaiserslautern. The joint topic of our talk was the measurement and modelling of fibre orientation of SMC. During SMC production, glass and carbon fibres are added to a polymer to increase its strength and resistance to deformation. The mechanical properties of the composite depend on the orientation of the fibres. The composite has higher stiffness and strength parallel to the alignment of the fibres.

Read more about Fraunhofer’s work here

Dominic’s focus was on the optical measurement of fibre orientation during the production process by polarisation imaging. The fibre orientation is measured in-situ directly in the production line and serves as input for the process simulation. In the process simulation – for which our tool FLUID can be used – the change in fibre orientation due to the compression process is predicted. Depending on the initial and the process conditions, the fibres can show significant alignment in the final part, implying that the mechanical behaviour is anisotropic.

In my part of the talk, I showed how to efficiently model the anisotropic nonlinear material behaviour using a three-scale modelling approach. Using the presented simulation chain, we can efficiently and accurately model the mechanical behaviour of SMC parts on a component level. This, in turn, allows the accurate virtual validation of designs using SMC composites necessary to increase the usage of SMC for the body structure of electric vehicles, thereby reducing its weight and extending their range.

ALMA, ALMA Eu Project, ALMA electric vehicle, Alma electric car, battery electric vehicle
This photo shows the work done by ALMA consortium partners within the project and their respective work packages.

Read: How ALMA is navigating lightweighting and related trade-offs

There was a vivid discussion in the meeting chat on validation and verification of the simulation results. In the ALMA project, we have used CT scans for the direct optical measurement of the fibre orientation. Other possibilities are the comparison between different software tools, as presented by Dr.-Ing. Martin Hohberg from Simutence GmbH.

This video explains Fraunhofer ITWM’s work in the ALMA project

Besides the mentioned presentation about the simulation approaches of Simutence GmbH, Max Schmidt from FibreCoat GmbH presented their technology of aluminium coated fibers which improves the EMI shielding of SMC. Both companies are recent start-ups from, in case of Simutence, the Karlsruher Institut für Technologie (KIT), and RWTH Aachen.

Also read about ALMA’s plans to decarbonise road transport

In summary, the event was a great possibility to showcase our work to the international SMC community, and to get a glimpse into the work of other companies on SMC technologies. The online format allowed for a large number of participants. While the limited discussion time was a slight drawback, participants could reach out directly to the presenters after the event, enabling more in-depth exchanges.

End of excerpt

This article is a contribution from Dr. Hannes Grimm-Strele from Fraunhofer ITWM, one of ALMA’s consortium partners in charge of experimental modelling of SMC materials.