PSI - Issue 21

E.F. Akbulut Irmak et al. / Procedia Structural Integrity 21 (2019) 190–197 E. F. Akbulut Irmak et al. / Structural Integrity Procedia 00 (2019) 000 – 000

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6. Conclusion Within this contribution, the mechanical properties of SLM AlSi10Mg specimens produced in different orientations were investigated. Test data were used to calibrate the Cazacu-Barlat anisotropic yield function. Clear tendencies were observed in tensile strengths and SLM specimens showed orientation dependency in elongation at break. It was detected by the scanning strategy that specimens have voids in their structure which influence the sensitivity of the specimens up against crack initiation under tensile loading. It was also proved that the size of pores affects tensile ductility of the material such as the intensity of pores. The negative effect of the pores on the deformation was proved by the fact that notched specimens initiated to break from the borderline where the support structure was formed. Such results made it necessary to consider pores in the structure by modeling to investigate the properties of the material. Therefore, specimens including randomly distributed pores were modeled and validated with the comparison of stress strain curves. Hockett-Sherby hardening law was implemented to extrapolate the flow curve. Cazacu-Barlat material model and GISSMO damage model were determined to predict the mechanical behavior of the specimens. On the other hand, it can be concluded that failure predictions with the material properties deduced from the experiments are quite sensitive to find out the results when the specimen includes critical pores. Acknowledgements Thanks are due to Jan Gierse from Direct Manufacturing Research Center (DMRC), Paderborn University for the support by supplying the specimens of the present study. References Ahmed, A., Majeed, A., Atta, Z., Guozhu, J., 2019. Dimensional quality and distortion analysis of thin-walled alloy parts of AlSi10Mg manufactured by selective laser melting. J. Manuf. Mater. Process. 3, 51. Andrade FXC., Feucht M., Haufe A., Neukamm F., 2016. An incremental stress state dependent damage model for ductile failure prediction. Int. J. Frac. 200 (1-2)127-150. Basaran M., 2011. Stress state dependent damage modeling with a focus on the Lode angle influence. Ph.D. thesis, RWTH Aachen Brinson, L. C., Shen, H., Oppenheimer, S. M., Dunand, D. C., 2006. Numerical modeling of pore size and distribution in foamed titanium. Mechanics of Materials 38, 933-944. Cazacu O., Plunkett B., Barlat F., 2006. Orthotropic yield criterion for hexagonal closed packed metals. Int. J. of Plasticity 22: 1171-1194 Hitzler, L., Janousch, C., Schanz, J., Merkel, M., Mack, F., Öchsner, A., 2016. Non-destructive evaluation of AlSi10Mg prismatic samples generated by Selective Laser Melting: influence of manufacturing conditions. Mat.-wiss.u. Werkstofftech. 47, 564 – 581 Kempen, K., Thijs, L., Yasa, E., Badrossamay, M., Verheecke, W., Kruth, J. P., 2011. Process optimization and micro structural analysis for selective laser melting of AlSi10Mg. In: SFF Symposium, Austin, Texas, USA. Kempen, K., Thijs, L., Van Humbeeck, J., Kruth, J. P., 2012. Material properties of AlSi10Mg produced by selective laser melting. Physics Procedia 39, 439-446 Kempen, K., Thijs, L., Van Humbeeck, J., Kruth, J. P., 2015. Processing AlSi10Mg by selective laser melting: parameter optimization and material characterisation. Mater. Sci. Technol. 31, 917 – 923 Kleszczynski, S., zur Jacobsmühlen, J., Sehrt, J., Witt, G., 2013. Mechanical properties of laser beam melting components depending on various processerrors. In: Kovács, G. L., Kochan, D. (Eds.), Digital Product and Process Development Systems. Lei, H., Liang, J.,Zhou, H., Dong, Z., Zhang, X., Shi, W., 2018. Study of size effect on microstructure and mechanical properties of AlSi10Mg samples made by selective laser melting. Materials 2018, 11 2463. LSTC, 2017. LS- DYNA Keyword User’s Manual - Volume II - Material Models, LS-DYNA R10 Plunkett B., Cazacu O., Barlat F., 2008. Orthotropic yield criteria for description of the anisotropy in tension and compression of sheet metals. Int. J. of Plasticity 24: 847-866 Tancogne-Dejean, T., Roth, C. C., Gorji, M. B., Pack, K., 2019. The third Sandia Fracture Challenge: deterministic and probabilistic modeling of ductile fracture of additively-manufactured material. Int J. Fract. Yadroitsev, I., Smurov, I., 2010. Selective laser melting technology: from the single laser melted track stability to 3D parts of complex shape. Phys. Procedia 5, 551 – 560