Sensitivity of Intervertebral Disc Finite Element Models to Internal Geometric and Non-geometric Parameters.
Sensitivity of Intervertebral Disc Finite Element Models to Internal Geometric and Non-geometric Parameters.
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DOI：
10.3389/fbioe.2021.660013
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发表时间：
2021
影响因子：
5.7
通讯作者：
Newell N
中科院分区：
文献类型：
--
作者：
Du Y;Tavana S;Rahman T;Baxan N;Hansen UN;Newell N
有限元模型可用于研究内部椎间盘 (IVD) 行为，而无需使用破坏性实验技术。简化的几何形状通常用于减少计算时间，或者因为无法从 CT 扫描中获取内部几何形状。本研究的目的是（1）研究改变终板和核-环边界的几何形状对模型响应的影响，以及（2）研究模型对材料和几何输入的敏感性，以及不同的建模方法（分级或一致的纤维束角度以及粘合或粘性层间接触）。根据牛 IVD 的 9.4 T MRI 开发了六种模型。模型具有两种不同的终板几何形状（从椎间盘中心到周边的简单弯曲轮廓，以及从 MRI 分段的精确几何形状），以及三种不同的 NP-AF 边界（线性、弯曲和分段）。模型承受轴向压缩载荷（在 0.1/s 的应变速率下达到 0.86 毫米）以及对刚度和应变分布的影响，并研究了建模方法的敏感性。具有最复杂几何形状（分段终板、弯曲 NP-AF 边界）的模型比具有最简单几何形状（弯曲终板、线性 NP-AF 边界）的模型刚度高 3.1 倍，尽管这种差异可能会被夸大，因为在复杂几何模型中分段终板会导致平均椎间盘高度更短。分段终板模型中的高曲率位置处的峰值应变接近终板，但在弯曲终板模型中未捕获到。对材料特性的敏感性、分级纤维角度、内聚性而非胶合层间接触以及 NP:AF 比率也存在差异。这些结果表明，有限元建模者必须注意确保几何形状真实，以便负载准确分布并通过 IVD。
Finite element models are useful for investigating internal intervertebral disc (IVD) behaviours without using disruptive experimental techniques. Simplified geometries are commonly used to reduce computational time or because internal geometries cannot be acquired from CT scans. This study aimed to (1) investigate the effect of altered geometries both at endplates and the nucleus-anulus boundary on model response, and (2) to investigate model sensitivity to material and geometric inputs, and different modelling approaches (graduated or consistent fibre bundle angles and glued or cohesive inter-lamellar contact). Six models were developed from 9.4 T MRIs of bovine IVDs. Models had two variations of endplate geometry (a simple curved profile from the centre of the disc to the periphery, and precise geometry segmented from MRIs), and three variations of NP-AF boundary (linear, curved, and segmented). Models were subjected to axial compressive loading (to 0.86 mm at a strain rate of 0.1/s) and the effect on stiffness and strain distributions, and the sensitivity to modelling approaches was investigated. The model with the most complex geometry (segmented endplates, curved NP-AF boundary) was 3.1 times stiffer than the model with the simplest geometry (curved endplates, linear NP-AF boundary), although this difference may be exaggerated since segmenting the endplates in the complex geometry models resulted in a shorter average disc height. Peak strains were close to the endplates at locations of high curvature in the segmented endplate models which were not captured in the curved endplate models. Differences were also seen in sensitivity to material properties, graduated fibre angles, cohesive rather than glued inter-lamellar contact, and NP:AF ratios. These results show that FE modellers must take care to ensure geometries are realistic so that load is distributed and passes through IVDs accurately.
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DOI：
10.1080/10255842.2010.493517
发表时间：
2011-01-01
影响因子：
1.6
作者：
Ayturk, Ugur M.;Puttlitz, Christian M.
通讯作者：
Puttlitz, Christian M.
影响因子：
3
作者：
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影响因子：
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作者：
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通讯作者：
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影响因子：
2.8
作者：
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通讯作者：
Mow, VC
影响因子：
2.9
作者：
CASSIDY, JJ;HILTNER, A;BAER, E
通讯作者：
BAER, E