Jian LiDiansheng ChenEmail authorYingying ZhangYan YaoZhongjun MoLizhen WangYubo FanEmail author
1.Robotic InstituteBeihang UniversityBeijingChina
2.Beijing Key Laboratory of Rehabilitation Technical Aids for Old-Age and Disability, and Key Laboratory of Rehabilitation Aids Technology and System of the Ministry of Civil AffairsNational Research Center for Rehabilitation Technical AidsBeijingChina
3.Beijing Advanced Innovation Center for Biomedical EngineeringBeihang UniversityBeijingChina
4.Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical EngineeringBeihang UniversityBeijingChina
In this study, mechanical properties of bionic porous structures with diagonal-symmetrical and midline-symmetrical unit cells were studied when the porosities were same. Three typical unit cells (Diamond (DO), Rhombic Dodecahedron (RD), and Octet Truss (OT)) were selected, in which DO has diagonal-symmetrical shape, while RD and OT share midline-symmetrical structure. Based on the same porosity, corresponding models were designed, and Ti6Al4V samples were manufactured by electron beam melting. Then, using Mechanical Properties Testing (MPT) and Finite Element Analysis (FEA) methodologies, mechanical properties and transmissions of different porous structures were evaluated. Besides, composition and details before and after printing were analyzed with Energy Dispersive Spectrometer (EDS), X-ray diffraction (XRD) and Scanning Electron Microscope (SEM). MPT results showed that midline-symmetrical shape would have superior compressive performance than diagonal-symmetrical shape, but opposite trend for the torsion performance, which were in line with FEA prediction. Furthermore, effective modulus of DO, RD and OT were 2.59 GPa, 4.89 GPa, and 1.77 GPa, approximating the mechanical properties of human bones. Additionally, manufacturing defects and discrepancies between FEA and MPT were found. This study would provide great helps for unit cell selection and initial mechanical properties matching for optimum bone implants.
bionic design porous implant mechanical properties unit cell additive manufacturing 3D printing
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