Experimental validation of 3D printed material behaviors and their influence on the structural topology design
- 447 Downloads
The purpose of this paper is to investigate the structures achieved by topology optimization and their fabrications by 3D printing considering the particular features of material microstructures and macro mechanical performances. Combining Digital Image Correlation and Optical Microscope, this paper experimentally explored the anisotropies of stiffness and strength existing in the 3D printed polymer material using Stereolithography (SLA) and titanium material using Selective Laser Melting (SLM). The standard specimens and typical structures obtained by topology optimization were fabricated along different building directions. On the one hand, the experimental results of these SLA produced structures showed stable properties and obviously anisotropic rules in stiffness, ultimate strengths and places of fractures. Further structural designs were performed using topology optimization when the particular mechanical behaviors of SLA printed materials were considered, which resulted in better structural performances compared to the optimized designs using ‘ideal’ isotropic material model. On the other hand, this paper tested the mechanical behaviors of SLM printed multiscale lattice structures which were fabricated using the same metal powder and the same machine. The structural stiffness values are generally similar while the strength behaviors show a difference, which are mainly due to the irregular surface quality of the tiny structural branches of the lattice. The above evidences clearly show that the consideration of the particular behaviors of 3D printed materials is therefore indispensable for structural design and optimization in order to improve the structural performance and strengthen their practical significance.
Keywords3D printing Topology optimization Lattice structure Material anisotropy Static loading test
This work is supported by National Key Research and Development Program (2017YFB1102800), National Natural Science Foundation of China (11722219, 51790171, 5171101743 and 11620101002), Key Research and Development Program of Shaanxi (2017KW-ZD-11 and 2017ZDXM-GY-059). The authors would like to thank Dr Jia Xin from Bright Laser Technology of Northwestern Polytechnical University, Prof Shi Yusheng and Dr Song Bo from Huazhong University of Technology for their support of 3D printing.
- 5.Aage N, Andreassen E, Lazarov BS, Sigmund O (2017) Giga-voxel computational morphogenesis for structural design—PROOF. Nature. https://doi.org/10.1038/nature23911
- 8.Duysinx P, Bendsøe MP (1998) Topology optimization of continuum structures with local stress constraints. Int J Numer Methods Eng 43:1453–1478. https://doi.org/10.1002/(SICI)1097-0207(19981230)43:8%3c1453::AID-NME480%3e3.0.CO;2-2 MathSciNetCrossRefMATHGoogle Scholar
- 15.Zhang WH, Zhou Y, Zhu JH (2017) A comprehensive study of feature definitions with solids and voids for topology optimization. Comput Methods Appl Mech Eng 325. https://doi.org/10.1016/j.cma.2017.07.004
- 18.Liu S, Li Q, Chen W et al (2015) H-DGTP—a Heaviside-function based directional growth topology parameterization for design optimization of stiffener layout and height of thin-walled structures. Struct Multidiscip Optim 52:903–913. https://doi.org/10.1007/s00158-015-1281-5 MathSciNetCrossRefGoogle Scholar
- 20.Gibson Ian, David Rosen BS (2013) Additive manufacturing technologies 3D printing, rapid prototyping, and direct digital manufacturing. Rapid Manuf Assoc. https://doi.org/10.1007/978-1-4939-2113-3
- 25.Zhu JH, Yang K, Zhang W (2016) Backbone cup—a structure design competition based on topology optimization and 3D printing. Int J Simul Multidiscip Des Optim 7Google Scholar
- 26.Gaynor AT, Meisel NA, Williams CB, Guest JK (2014) Topology optimization for additive manufacturing: considering maximum overhang constraint. In: 15th AIAA/ISSMO Multidiscip Anal Optim Conf 1–8. https://doi.org/10.2514/6.2014-2036
- 29.Salmoria GV, Ahrens CH, Fredel M et al (2005) Stereolithography somos 7110 resin: mechanical behavior and fractography of parts post-cured by different methods. Polym Test 24:157–162. https://doi.org/10.1016/j.polymertesting.2004.09.008 CrossRefGoogle Scholar
- 33.Witt WK, Hoppmann II, Buxbaum RS (1953) Determination of elastic constants of orthotropic materials with special reference to laminates. Johns Hopkins Univ Baltimore MD Inst for Cooperative ResearchGoogle Scholar
- 38.Wang L, Liu D, Yang Y et al (2017) A novel method of non-probabilistic reliability-based topology optimization corresponding to continuum structures with unknown but bounded uncertainties. Comput Methods Appl Mech Eng 326:573–595. https://doi.org/10.1016/j.cma.2017.08.023 MathSciNetCrossRefGoogle Scholar