PSI - Issue 56

Dan Micota et al. / Procedia Structural Integrity 56 (2024) 144–152 Dan Micota / Structural Integrity Procedia 00 (2019) 000 – 000

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well as test results and comparisons with lower wall thickness injected plate specimens from previous work from the authors is has also detailed a comprehensive workflow for modeling and simulating SFRP injected parts/components, starting with injection molding simulations (Autodesk Moldflow), material modeling with Digimat MX, FOT mapping with Digimat MAP and FEA solver for structural simulation ANSYS Mechanical. The main conclusions that can be drawn are the following:  Good results were obtained from the increased specimens thickness tests considering the shape of the stress strain curves and the small dispersion of the obtained data.  The influence of wall thickness on the mechanical properties of SFRP injected components is substantial, growth of wall thickness leading to a general decrease in properties.  This tendency is accentuated longitudinally in terms of rigidity and strength, and quite unobservable transversally.  Strains at break decrease over the whole orientation range for increased wall thickness.  The main reason for this phenomenon is due to the mid layer fountain effect, as the wall thickness increases the central melt layer that freezes last is thicker, and it freezes with an un-oriented fiber structure.  Also, the overall anisotropy at higher wall thicknesses decreases as the difference in FOT between layers is decreased, thus the stress-strain curves are more closely spread in Y direction (stress axis). Future directions might be the following:  Tensile tests for both material at lower (-40°C) and higher (up to +120°C) temperatures.  Improve the calibration of the material model using Digimat.  Compare material model calibration results with Ansys Material Designer.  Validate the material models using a mechanical test for an injected automotive part. Acknowledgements The work leading to this paper was partially supported by InoHubDoc project POCU/993/6/13/153432 and by the European Union's Horizon 2020 research and innovation program (H2020-WIDESPREAD-2018, SIRAMM) under grant agreement no. 857124. Results were disseminated in the SIRAMM project, final conference SIRAMM 23 in Timisoara, Romania. Special thanks to the Solvay Group for providing materials and support. Thanks, are also extended to Vitesco Technologies company for support in specimen elaboration, technical and specialized software support. References 527-1, I. (2016). Plastics — Determination of tensile properties — Part 1: General principles (Vol. 2016, pp. 2 – 7). 527-2, I. (2016). Plastics — Determination of tensile properties — Part 2: Test conditions for moulding and extrusion plastics . 2016 , 2 – 7. Bernasconi, A., Davoli, P., Basile, A., & Filippi, A. (2007). Effect of fibre orientation on the fatigue behaviour of a short glass fibre reinforced polyamide-6. International Journal of Fatigue , 29 (2), 199 – 208. https://doi.org/10.1016/j.ijfatigue.2006.04.001 Castagnet, S., Nadot-Martin, C., Fouchier, N., Conrado, E., & Bernasconi, A. (2021). Fatigue life assessment in notched injection-molded specimens of a short-glass fiber reinforced Polyamide 6 with different injection gate locations. International Journal of Fatigue , 143 (September 2020), 105968. https://doi.org/10.1016/j.ijfatigue.2020.105968 Choi, N. S., & Takahashi, K. (1992). Stress fields on and beneath the surface of short-fiber-reinforced composites and their failure mechanisms. Composites Science and Technology , 43 (3), 237 – 244. https://doi.org/10.1016/0266-3538(92)90094-J Digimat 2022.4 MAP User's Guide Digimat MAP User's Guide . (1992). https://simcompanion.hexagon.com Digimat 2022.4 MX User's Guide Digimat MX User's Guide . (1992). https://simcompanion.hexagon.com Hassan, A., Yahya, R., Yahaya, A. H., Tahir, A. R. M., & Hornsby, P. R. (2004). Tensile, impact and fiber length properties of injection-molded short and long glass fiber-reinforced polyamide 6,6 composites. Journal of Reinforced Plastics and Composites , 23 (9), 969 – 986. https://doi.org/10.1177/0731684404033960 Holmström, P. H., Hopperstad, O. S., & Clausen, A. H. (2020). Anisotropic tensile behaviour of short glass-fibre reinforced polyamide-6. Composites Part C: Open Access , 2 , 100019. https://doi.org/10.1016/j.jcomc.2020.100019 Huang, Z. M., Zhang, C. C., & Xue, Y. De. (2019). Stiffness prediction of short fiber reinforced composites. International Journal of Mechanical Sciences , 161 – 162 . https://doi.org/10.1016/j.ijmecsci.2019.105068