钛合金变形Gyroid单元梯度多孔结构设计与分析

Design and analysis of gradient porous structures for titanium alloy deformation Gyroid units

摘要:

摘 要: 骨组织工程中，三周期极小曲面（Triply Periodic Minimal Surfaces，TPMS）多孔结构研究日益广泛，目前国内外的研究主要集中在常规TPMS多孔结构，有关变形TPMS多孔结构研究较少，而变形TPMS单元多孔结构在一定方向上具有力学性能优势。本文研究一种具有径向和轴向孔径梯度的变形Gyroid单元多孔结构参数化设计方法，采用激光选区熔化成形（Selective Laser Melting，SLM）技术，制备出孔隙率为60%和75%的钛合金变形Gyroid单元梯度多孔结构样件。使用有限元法(Finite Element Method, FEM)对四组梯度多孔支架模型及两组均质模型进行静力学仿真分析，对制备的钛合金梯度多孔样件进行力学性能测试，并与已测试过的均质样件进行力学性能对比分析。有限元计算结果与力学性能试验结果共同表明：变形Gyroid单元多孔结构力学性能随孔隙率升高而降低，孔隙率相同时，径向梯度多孔支架力学性能优于均质多孔支架，更适用于皮质骨的骨缺损修复，轴向梯度多孔支架力学性能相比均质多孔支架有所减弱，更适用于松质骨。

关键词:变形TPMS多孔结构;孔径梯度;钛合金;力学性能;有限元法

Abstract:

Abstract: In bone tissue engineering, the studies on porous structures of Triply Periodic Minimal Surfaces (TPMS) are increasingly extensive. At present, the studies at home and abroad mainly focus on conventional TPMS porous structures, while the studies on deformed TPMS porous structures are few. The porous structure of deformed TPMS element has the advantage of mechanical properties in a certain direction. In this paper, a parametric design method of deformed Gyroid cell porous structure with radial and axial aperture gradients is studied. The deformed Gyroid cell porous structure samples with 60% and 75% porosity of titanium alloy are prepared by Selective Laser Melting (SLM) technology. The Finite Element Method (FEM) was used to carry out static simulation analysis on four kinds of gradient porous scaffold models and two kinds of uniform models, and the mechanical properties of the prepared titanium alloy gradient porous samples were tested, and the mechanical properties were compared and analyzed with those of the tested uniform samples. Finite element calculation results and the mechanical performance test result shows that the mechanical properties of porous structure deformation Gyroid unit decreases with porosity increased, while the porosity is the same,the radial gradient of mechanical properties of porous scaffolds is better than that of uniform porous scaffolds, more suitable for cortical bone defects of bone repair,and axial gradient of mechanical properties of porous scaffolds compared with uniform porous scaffolds weakened, more suitable for the cancellous bone.

Key words:Deformed TPMS porous structure; aperture gradient; titanium alloy; mechanical properties; the finite element method