基于SLS工艺尼龙假脚的结构设计

The Structural Design of Nylon Prosthetic Foot Based on SLS Process

采用选区激光烧结(selective laser sintering,SLS)3D打印工艺生产的一体式尼龙小腿假肢相比传统小腿假肢在轻量化方面有明显优势,但穿戴过程中会出现脚底开裂或弹性不足的问题,为此提出一种基于SLS成型工艺的假脚结构优化设计方法。首先,介绍足部工况和假脚的设计要求,然后对SLS工艺参数及打印尼龙材料力学性能进行研究;其次,借助有限元分析方法获得步行时跖屈和背屈工况条件下假脚的应力分布状态,对假脚结构进行设计;最后,对结构调整后的打印假脚进行实验研究。结果表明基于SLS成型工艺和有限元方法设计的假脚能够满足实际需要,可以提高SLS打印尼龙小腿假肢的设计效率。

Compared with the traditional lower limb prosthesis,the integrated nylon lower limb prosthesis produced by selective laser sintering has significant advantages in terms of lightweight.To solve the problem of foot cracking or insufficient elasticity during wearing,an optimal structural designing method of digital prosthesis based on the SLS process is proposed.Firstly,the design requirements of foot working condition and prosthetic foot are introduced.The process parameters of the SLS and the mechanical properties of printed nylon materials are therefore studied.To optimize the structure of the prosthetic foot,the stress distribution of the prosthesis under the condition of plantfoot flexion and dorsalflexion during walking is obtained by using the finite element method.Finally,the experiment of the optimized printing foot is conducted and validated by the simulation results.It demonstrates that the designed prosthetic foot based on the SLS process and finite element method can meet the actual requirements and improve the design efficiency.