碳化硅-碳复合材料用于小关节假体:生物力学研究及三维有限元分析

Silicon carbide-carbon composites for small joint prosthesis: a three-dimensional finite element model for biomechanical study

背景:碳化硅-碳复合材料应用广泛,但其在医学假体材料领域无相关实验研究,效果尚不明确。目的:探究新型碳化硅-碳复合材料的力学性能,采用三维有限元分析法模拟小关节的受力情况,论证其作为人工小关节假体替代材料的可行性。方法:将规定尺寸的碳化硅-碳复合材料与传统碳/碳复合材料放置于电子万能试验机中,测定并计算材料的压缩弹性模量、抗压缩强度、最大抗压缩力、弯曲弹性模量、抗弯强度及最大抗弯力,随后测定并计算材料的摩擦系数、磨损体积和质量磨损率。应用三维有限元分析法,将第三掌骨有限元模型分别定义碳/碳复合材料及碳化硅-碳复合材料单元类型后,给予轴向200 N的作用力,分析其总位移及节点应力情况。结果与结论:碳化硅-碳复合材料的压缩弹性模量、抗压缩强度、最大抗压缩力、弯曲弹性模量、抗弯强度及最大抗弯力高于碳/碳复合材料(P<0.05),摩擦系数、磨损体积和质量磨损率、最大节点应力及最大总位移低于碳/碳复合材料(P<0.05)。结果说明,碳化硅-碳复合材料具有良好的力学性能、抗磨损性能,抗压缩形变及抗应力作用。

BACKGROUND： Silicon carbide-carbon（C/C-Si C） composite materials are widely used, but no relevant experimental studies on medical prosthesis materials have been reported. OBJECTIVE： To demonstrate the feasibility of C/C-SiC composite materials as a substitute for facet joint prosthesis based on the biomechanical research and three-dimensional finite element analysis. METHODS： The predetermined size C/C-Si C composites and traditional carbon/carbon（C/C） composite materials were placed in an electronic universal testing machine, to measure and calculate material compressive elastic modulus, compressive strength, maximal anticompression force, flexural modulus, bending strength and maximal antibending force. Afterwards friction coefficient, wear volume and weight wear rate were measured. Using three-dimensional finite element analysis, finite element models of the third metacarpal bone were defined as C/C and C/C-Si C composite element types, respectively. 200 N axial force was applied to analyze the total displacement and node stress. RESULTS AND CONCLUSION： Compressive elastic modulus, compressive strength,maximal anticompression force, flexural modulus, bending strength and maximal antibending force of C/C-Si C composites were significantly higher than those of the C/C materials（P〈0.05）; friction coefficient, wear volume, weight wear rate, total displacement as well as node stress of C/C-Si C composites were significantly lower than those of C/C materials（P〈0.05）. These results prove that C/C-SiC composite has favorable mechanical properties, antiwear ability, compression resistance and stress resistance.