High-resolution finite element models with tissue strength asymmetry accurately predict failure of trabecular bone
High-resolution finite element models with tissue strength asymmetry accurately predict failure of trabecular bone
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DOI：
10.1016/s0021-9290(00)00149-4
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发表时间：
2000-12-01
影响因子：
2.4
通讯作者：
Keaveny, TM
中科院分区：
文献类型：
--
作者：
Niebur, GL;Feldstein, MJ;Keaveny, TM
使用基于微结构的计算模型预测小梁失效的能力将极大地促进小梁结构-功能关系、多轴强度和组织重塑的研究。我们假设小梁骨的高分辨率有限元模型（包括组织水平上的皮质样强度不对称性）可以预测多种加载模式下小梁骨的明显水平失效。应用具有不对称组织屈服应变的拉伸和压缩双线性本构模型来模拟七个牛胫骨样本的高分辨率有限元模型的失效。当组织主应变超过组织屈服应变时，组织模量降低95%。首先根据样本特定的表观模量实验测量来校准线性模型的有效组织模量，产生（平均值 +/- S.D.）18.7 +/- 3.4 GPa 的有效组织模量。接下来，对单个样本进行参数研究，以估计组织水平拉伸和压缩屈服应变。然后将这些值（0.60% 拉伸应变和 1.01% 压缩应变）用于所有七个样本的非线性分析，以预测表观拉伸、压缩和剪切载荷的失效。与之前测量的相同类型骨骼的表观屈服特性相比，模型预测的失效应力和应变对于任何载荷情况都没有统计差异 (p > 0.15)。使用对称组织强度无法匹配实验数据。这些发现表明，一旦校准了有效组织模量并使用均匀但不对称的组织失效应变，所得模型就可以以出色的精度捕获表观强度行为。因此，这些计算模型已经达到了一定的保真度水平，可以作为真实样本破坏性机械测试的替代品。 (C) 2000 Elsevier Science Ltd. 保留所有权利。
The ability to predict trabecular failure using microstructure-based computational models would greatly facilitate study of trabecular structure-function relations, multiaxial strength, and tissue remodeling. We hypothesized that high-resolution finite element models of trabecular bone that include cortical-like strength asymmetry at the tissue level, could predict apparent level failure of trabecular bone for multiple loading modes. A bilinear constitutive model with asymmetric tissue yield strains in tension and compression was applied to simulate failure in high-resolution finite element models of seven bovine tibial specimens. Tissue modulus was reduced by 95% when tissue principal strains exceeded the tissue yield strains. Linear models were first calibrated for effective tissue modulus against specimen-specific experimental measures of apparent modulus, producing effective tissue moduli of (mean +/- S.D.) 18.7 +/- 3.4 GPa. Next, a parameter study was performed on a single specimen to estimate the tissue level tensile and compressive yield strains. These values, 0.60% strain in tension and 1.01% strain in compression, were then used in non-linear analyses of all seven specimens to predict failure for apparent tensile, compressive, and shear loading. When compared to apparent yield properties previously measured for the same type of bone, the model predictions of both the stresses and strains at failure were not statistically different for any loading case (p > 0.15). Use of symmetric tissue strengths could not match the experimental data. These findings establish that, once effective tissue modulus is calibrated and uniform but asymmetric tissue failure strains are used, the resulting models can capture the apparent strength behavior to an outstanding level of accuracy. As such, these computational models have reached a level of fidelity that qualifies them as surrogates for destructive mechanical testing of real specimens. (C) 2000 Elsevier Science Ltd. All rights reserved.