The Lamera case study aimed at predicting the formability and performance of Hybrix™ material through Finite Elements (FE) simulation and evaluate its properties through advanced characterisation tests.

The present case study has been executed for three different material specifications and configurations for Hybrix™, with carbon steel as face materials.

A methodology was established to characterise the material core and experimental Computer Aided Engineering (CAE)-based analyses were performed to predict parameters in order to validate the calibrated material model and failure criteria. Simulation software was used to perform numerical analyses on the stamping operation of a battery box and tools with different forming features.

View of Hybrix™ material composition (0.5-3.4 mm thickness) with a total weight of 1.0 to 8.5 kg/m² depending on the configuration

The simulation results indicated that the energy absorption of the lightweight battery housing (almost 40% lighter than competitors) could be improved compared to the corresponding solid steel material/product.

Taking simulation results into account, a set of Electric Vehicle battery boxes with different configurations were designed with the Hybrix™ material to demonstrate the material performance. LAMERA AB performed the stamping operation of the battery box covers, which were delivered to an automotive end-user for further material investigation and component analyses.

Numerical investigations using CAE tools (IMPETUS Afea & HyperWorks)

Various experimental methods have been used to predict and evaluate material performance before and after stamping, based on the end-user requirements. One of those is the T-Peel test, used for the peel resistance of adhesives, that was carried out in accordance with ASTM D1876, which should be fulfilled if a multi-layer material is approved for automotive industries. This test was complemented with the procedure described in ASTM D5528 to complement the fracture behaviour and other tests carried out by the end user to check the presence of stamping cracks, delamination and other.

Conclusions of this case study indicate that is possible to use CAE tools to accurately predict materials performance and that these tools provide valuable assistance when investigating which material’s configuration is more suitable for a specific geometry and selected forming process. The battery house developed with the Hybrix™ material fulfilled the end-user requirements according to the performed test procedures, positioning the material as a lightweight solution suitable for Electric Vehicles.

Specific tests and simulation methodologies applied for sandwich materials including:

• Peel test
• LS Dyna simulation