• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2017, Vol. 53 ›› Issue (5): 175-180.doi: 10.3901/JME.2017.05.175

• 制造工艺与装备 • 上一篇    下一篇

面向3D打印可变模量金属假体的微结构设计*

康建峰1, 王, 玲1, 孙畅宁1, 李涤尘1,2, 靳忠民1,3   

  1. 1. 西安交通大学机械制造系统工程国家重点实验室 西安 710049;
    2. 陕西恒通智能机器有限公司 西安 710049;
    3. 利兹大学机械工程学院 利兹 LS2 9JT 英国
  • 出版日期:2017-03-05 发布日期:2017-03-05
  • 作者简介:

    康建峰,男,1988年出生,博士研究生。主要研究方向为仿生制造与医疗修复工程。

    E-mail:kjfmg@sina.com

    王玲(通信作者),女,1979年出生,博士,副教授,博士研究生导师。主要研究方向为生物制造、生物力学、生物摩擦学、组织工程。

    E-mail:menlwang@mail.xjtu.edu.cn

  • 基金资助:
    * 陕西省科技统筹工程计划(2014KTZB01-02-02)和中央高校基本科研业务费专项资金资助项目; 20160311收到初稿,20160918收到修改稿;

Microstructure Design for 3D Printed Metal Prosthesis of Adjustable Modulus

KANG Jianfeng1, WANG Ling1, SUN Changning1, LI Dichen1,2, JIN Zhongmin1,3   

  1. 1. State Key Laboratory for Manufacturing Systems Engineering, Xi’an Jiaotong University, Xi’an 710049;
    2. Shaanxi Hengtong Intelligent Machines Co. Ltd., Xi’an 710049;
    3. School of Mechanical Engineering, University of Leeds, Leeds LS2 9JT, UK
  • Online:2017-03-05 Published:2017-03-05

摘要:

为了解决假体与骨的弹性模量存在较大差异而造成应力遮挡的问题,基于3D打印在制造多孔微结构的优势,将假体设计为多孔结构能有效降低模量,缓解应力遮挡。但是,如何优化微结构几何参数以实现假体模量的最佳匹配仍然没有得到解决。因此,提出了一种面向3D打印的可变模量金属假体的微结构设计方法,旨在获得与宿主骨模量相匹配又具有可加工性的生物型假体。针对体心立方单元(BCC)和增强体心立方单元(RBCC),采用有限元法计算了两种多孔单元沿轴向、面对角线和体对角线方向的弹性模量,建立了单元弹性模量与支柱直径的函数关系,分析了单元各向异性随支柱直径变化的规律,研究了棱边直径和单元尺寸对单元弹性模量的影响。结果表明:在加工精度范围内,通过减小支柱直径能实现单元等效弹性模量与骨模量一致性要求;在各向同性上BCC单元要优于RBCC单元,而且增大棱边直径有助于提高单元各向同性;由于BCC单元能实现相邻不同模量的单元界面连续拼接,故选用BCC单元构建模量可调的假体,可变模量范围为15.9~100 GPa。该设计方法可用于构建具有模量梯度结构的生物假体,以实现关节应力最优分布。

关键词: 弹性模量, 多孔结构, 金属假体, 孔隙率, 3D打印

Abstract:

In order to avoid the stress shielding caused by the difference of elastic modulus between human bone and the prosthetic implant, porous design can be effective to reduce the effectively modulus of the prostheses. However, how to optimize the microstructure geometric parameters for better matching with the bone tissue has not been solved yet. By taking the advantages of 3D printing technology on customized microstructure manufacture, a design method to adjust the modulus of the metal prosthetic for better matching with the bone tissue is proposed in this study, to obtain satisfactory and manufacturable prosthesis by 3D printing. The elastic modulus of two porous lattices along the edge direction, surface diagonal and body diagonal have been calculated individually by implementing the finite element method (FEM). Thereafter the functional relationship between the equivalent elastic modulus and the strut diameter has been established. The anisotropy characteristics of the microstructure has been analyzed along with the change of the strut diameter, and the influence of the edge diameter and the lattice size on the elastic modulus has been investigated as well. Within the limitation of manufacturing capacity of metal 3D printing, the calculated equivalent elastic modulus of the prosthesis were found to be consistent with those of the human bone by reducing the strut diameter. The body-centered cubic (BCC) is superior to reinforced body-centered cubic (RBCC) in terms of the isotropy characteristics. The BCC unit implementing successfully interface connection of adjacent and different modulus lattice can be used to construct prosthesis of adjustable modulus, and the allowable range of elastic modulus is 15.9-100 GPa. The proposed method can be applied to build prosthesis with gradient modulus gradient in order to achieve the optimized stress distribution within the joints.

Key words: elastic modulus, metal prosthesis, porosity, porous structure, 3D Printing