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  • Create Date January 20, 2025
  • Last Updated January 20, 2025

Among metal additive manufacturing technologies, direct energy deposition (DED) processes have the advantage of being easily integrable in a manufacturing chain with other conventional technologies. This characteristic can be exploited by designing reinforcement structures to be added by DED onto pre-existing subcomponents to tailor the part’s mechanical properties while keeping the part lightweight.
This deliverable reports a virtual analysis under defined high-speed load conditions to identify design strategies to optimise the crashworthiness of hybrid components. A first set of simulations considering a rectangular extruded profile is carried out to evaluate the beneficial effect of the AVFFs. This system, representative of the operating scenario of a crash box of the front rail of the vehicle, is selected to perform a systemic study of the influence of the AVFF’s geometrical parameters on the crash resistance.

However, the integration of AM structures to tailor the mechanical behaviour of automotive safety systems needs the development of new concepts of simulations and advanced materials models. For that, experimentally calibrated material models are built to enhance the reliability of the analysis. In particular, the advanced material models consider the triaxiality, the strain rate and a probabilistic failure of the component, not considered before. Under this condition, the analysis reveals that conceiving systems in which the AVFFs are deformed along the compression direction is highly beneficial, leading to an increment of the energy absorbed between 15% and 20% as a result of adding <5% of mass onto the profile surface.

The results of the mechanical analysis are then compared with finite elements numerical simulations of the deposition process, comprising thermo-elastic deformation and material deposition, to predict the bending and reinforcement of the processed substrate. In particular, the model includes the deterministic prediction of the deposition profile as a function of the process parameters and a few condition-specific coefficients: once calibrated, the model is used to compare the numerical and experimental residual deformation of the reinforced sample, obtaining promising agreement. The validated model is then used to simulate the manufacturing process of the geometries selected after the mechanical study to assess the residual stress and the deformations of the substrate and define the suitable AVFF geometries to be manufactured for the experimental test campaign planned in the next period of the project.


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