皮质骨试样制备及其材料参数识别方法研究  

A Study on Cortical Bone Specimens Preparation and Method to Calculate the Mechanical Parameters

作　　者：张冠军[1] 邓先攀 杨洁[1] 翟乃川 邓小朋[1] 曹立波[1] 

机构地区：[1]湖南大学汽车车身先进设计制造国家重点实验室,长沙410082

出　　处：《中国生物医学工程学报》2017年第1期75-82,共8页Chinese Journal of Biomedical Engineering

基　　金：国家自然科学基金(51205118);中央高校基本科研业务费(531107040162);湖南大学汽车车身先进设计制造国家重点实验室自主研究课题(51475002)

摘　　要：有限元方法已经成为损伤生物力学研究的重要手段,准确的皮质骨材料本构参数对研究人体冲击损伤和人工骨骼等医学问题具有重要意义。基于长骨皮质骨的生理结构,提出批量制备高精度规则试样的加工方法,并开展准静态三点弯曲试验;采用基于梁理论和基于特定样本有限元模型优化反求两种方法,研究皮质骨材料的各向异性和区域差异,并通过线性回归分析建立两种识别方法所得材料参数的回归模型。制备横向和轴向试样各16个,所提出的试样制备方法能够保证试样间的尺寸偏差不超过4%,基于梁理论方法求得的新鲜牛股骨皮质骨轴向和横向试样的杨氏模量分别为(21.70±3.33)GPa和(14.47±2.10)GPa,极限应力分别为(249.21±38.83)MPa和(106.81±21.05)MPa,极限应变分别为1.95%±0.35%和1.06%±0.20%,与文献结果吻合。对利用优化方法和梁理论方法求得的杨氏模量、屈服应力和有效塑性应变进行线性回归分析,回归模型拟合精度分别为96.4%、98.7%和89.3%(P<0.05)。研究结果表明,所提出的试样制备方法能够高效地加工尺寸精度较高的规则试样,并良好地保持试样的生物力学特性。在皮质骨准静态三点弯曲试验中,基于特定样本有限元模型的材料参数反求方法能够识别更准确的材料本构参数,而基于梁理论识别参数的回归模型则能够快速准确地预测皮质骨的弹性模量、屈服应力和有效塑性应变。The finite element method has become an important means of injury biomechanics,accurate cortical bone material constitutive parameters are important for the study of human impact injury and artificial bone. In this study,a method for processing high precision regular specimens is proposed and a quasi-static three-point bending test was applied. The beam theory and the optimization methodology with specimen-specific finite element models were applied to discuss the anisotropy and regional difference of cortical bone material,and a regression mode of material parameters obtained by the two methods was established based on linear regression analysis. Sixteen transverse and axial specimens were prepared, the proposed method can control the dimensions of specimens deviation of less than 4%. Using beam theory,Young＇ s modulus of fresh bovine cortical bone in the axial and transverse was（ 21. 70 ± 3. 33） GPa and（ 14. 47 ± 2. 10） GPa,ultimate stress was（ 249. 21 ± 38. 83） MPa and（ 106. 81 ± 21. 05） MPa,and the ultimate strain was 1. 95% ± 0. 35% and1. 06% ± 0. 20%,respectively,which were consistent with results reported by literatures. Linear regression analysis was applied to Young＇s modulus,yield stress and effective plastic strain obtained by beam theory and optimization,the fitting precision of the regression model was 96. 4%,98. 7% and 89. 3%（ P〈0. 05）,respectively. Results showed that the proposed method can efficiently prepare specimens with high dimensional accuracy and the biomechanical properties of the specimens were well maintained. In the quasi-static three point bending test of cortical bone,accurate material constitutive parameters were obtained by the optimization methodology with specimen-specific finite element models,and elastic modulus,yield stress and effective plastic strain were predicted quickly and accurately by beam theory based on the regression mode.

关 键 词：皮质骨 材料参数 优化 线性回归 损伤生物力学 

分 类 号：R318[医药卫生—生物医学工程]