Gray H A, Zavatsky A B, Taddei F, Cristofolini L, Gill H S
Department of Engineering Science, Oxford University, Oxford, UK.
Proc Inst Mech Eng H. 2007 Apr;221(3):315-24. doi: 10.1243/09544119JEIM119.
Composite bones are synthetic models made to simulate the mechanical behaviour of human bones. Finite element (FE) models of composite bone can be used to evaluate new and modified designs of joint prostheses and fixation devices. The aim of the current study was to create an FE model of a composite tibia and to validate it against results obtained from a comprehensive set of experiments. For this, 17 strain rosettes were attached to a composite tibia (model 3101, Pacific Research Laboratories, Vashon, Washington, USA). Surface strains and displacements were measured under 13 loading conditions. Two FE models were created on the basis of computed tomography scans. The models differed from each other in the mesh and material properties assigned. The experiments were simulated on them and the results compared with experimental results. The more accurate model was selected on the basis of regression analysis. In general, experimental strain measurements were highly repeatable and compared well with published results. The more accurate model, in which the inner elements representing the foam were assigned isotropic material properties and the elements representing the epoxy layer were assigned transversely isotropic material properties, was able to simulate the mechanical behaviour of the tibia with acceptable accuracy. The regression line for all axial loads combined had a slope of 0.999, an intercept of -6.24 microstrain, and an R2 value of 0.962. The root mean square error as a percentage was 5 per cent.
复合骨是为模拟人体骨骼的力学行为而制作的合成模型。复合骨的有限元（FE）模型可用于评估关节假体和固定装置的新设计及改进设计。本研究的目的是创建一个复合胫骨的有限元模型，并根据一系列全面实验获得的结果对其进行验证。为此，将17个应变片附着在一个复合胫骨（型号3101，太平洋研究实验室，美国华盛顿州瓦申）上。在13种加载条件下测量表面应变和位移。基于计算机断层扫描创建了两个有限元模型。这两个模型在网格划分和分配的材料属性方面有所不同。在它们上面模拟实验，并将结果与实验结果进行比较。根据回归分析选择更精确的模型。总体而言，实验应变测量具有高度可重复性，且与已发表的结果比较吻合。更精确的模型中，代表泡沫的内部单元被赋予各向同性材料属性，代表环氧树脂层的单元被赋予横观各向同性材料属性，该模型能够以可接受的精度模拟胫骨的力学行为。所有轴向载荷综合起来的回归线斜率为0.999，截距为 -6.24微应变，R2值为0.962。均方根误差百分比为5%。
