均匀材料和基于CT灰度值材料的股骨、胫骨有限元分析

The Finite Element Analysis of Femur and Tibia for Homogeneous Materials and CT Gray Value Based Materials

为了定量分析骨量分布与载荷环境的关系,基于CT数据建立了大鼠股骨和胫骨的三维有限元模型,并分别赋予均匀的材料特性和基于CT灰度值的材料特性,用描述骨密度与力学刺激关系的算法来评估简单生理载荷下两种材料模型的有限元分析结果。结果表明,基于CT灰度值模型的有效应力和应变能密度分布与CT灰度分布比较相似,相关系数也较均匀材料模型更高;而且,基于CT灰度值模型的抗断裂能力更强;除此之外,这类模型也更符合骨再造平衡时的力学刺激均匀性假设。基于CT灰度值的有限元模型符合骨的功能适应性原理,可用于进行骨骼内部受力、变形和断裂分析,以及骨再造的数值仿真等研究。

In order to investigate the relationship between the bone amount distribution and the loading environment,the three dimensional finite element models of rat femur and tibia were established based on the CT data,and the homogeneous material property and the material property based on the CT gray value were assigned to the models respectively.The algorithms describing the relationship between the bone density and mechanical stimulus were used to evaluate the analysis results of the two kinds of models.The results shown that the distributions of the effective stress and the strain energy density from the CT gray value based model were similar to the CT gray distribution,and the correlation coefficients were higher than that of the homogeneous material model.The CT gray value based model could bear the physiological loading and avoid bone fracture.Besides,the CT gray value based model conformed to the hypothesis that the mechanical stimulus would be uniform when the bone remodeling came to equilibrium.In summary,the CT gray value based model coincides with the bone adaptation principle,and can be used to analyze the loading,distortion and fracture of the internal bone tissue,as well as the bone remodeling simulation.