目的 运用有限元方法分析手性蜂窝夹层结构椎体植入物的应力分布规律,为指导椎体压缩性骨折的临床治疗提供理论依据。 方法 建立三韧带手性蜂窝夹层结构椎体植入物三维有限元模型,结合正交实验法和面内外尺寸效应分析进行结构参数优化设计,并分析 5 种不同工况下的应力和应力分布。 结果 应力峰值最小的结构参数组合为:胞元壁厚 0. 28 mm,面板厚度 0. 8 mm,胞元高度 0. 2 mm,韧带长度 0. 6 mm,应力峰值出现在蜂窝层边缘靠近上下面板的部分,最大应变位于上面板边缘未受蜂窝芯子支撑的部分。 结论 优化设计后的手性蜂窝夹层结构满足人体生理载荷,植入椎体后应力峰值比正六边形蜂窝夹层结构更小,应力分布更均匀,适合作为椎体植入物基本结构。

Objective To analyze stress distributions of vertebral implants with chiral honeycomb sandwich structure by finite element method, so as to provide a theoretical basis for the clinical treatment of vertebral compression fractures. Methods The three-dimensional (3D) finite element model of the vertebral implant with trichiral honeycomb sandwich structure was constructed.The structural parameters were optimized by combining orthogonal experiment with the in-plane and out-of plane size effects,and the stress and stress distributions under five different working conditions were analyzed. Results The combination of structural parameters with the minimum peak stress was as follows: cell wall thickness 0.28 mm, panel thickness 0.8 mm, cell height 0.2 mm, ligament length 0.6 mm.The peak stress occurred at the edge of the honeycomb core near the upper and lower panels, and the maximum strain was located at the edge of the upper panel which was not supported by the honeycomb core. Conclusions After optimized design, the chiral honeycomb sandwich structure could meet the physiological load of human body, and the peak stress after vertebral implantation was smaller than that of the regular hexagonal honeycomb sandwich structure, and the stress distribution was more uniform, which was suitable for the basic structure of vertebral implants.

国家自然科学基金项目(11472185)