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Description
High-strength steels are widely used in the body in white of vehicles offering a good balance between crashworthiness and lightweight design. The increased requirements of heavier electric vehicles in terms of fatigue resistance and crashworthiness highlighted that chassis parts have remarkable lightweighting potential. However, applying these grades in chassis parts is not straightforward, as the forming processes like trimming may introduce surface defects that compromise the fatigue resistance of the component. This work aims to present a material selection strategy for the applicability of high-strength steels in chassis parts of electrical vehicles. The proposed approach allows the evaluation of the key parameters of the chassis parts in a simple way. The crash performance is evaluated through fracture toughness using the essential work of fracture (EWF) methodology. The method is applied to thin, high-strength steel employing double-edge notched tensile specimens (DENT). On the other hand, fatigue performance is investigated in terms of fatigue resistance for notched and unnotched specimens. The results for different complex-phase and dual-phase steels show a good agreement between the EWF and the fatigue notch factor. The method could help apply high-strength steel to chassis parts, as designers will have a tool to focus the expensive fatigue tests on the best material candidates.