Wang Yawei, Wang Lizhen, Du Chengfei, Mo Zhongjun, Fan Yubo
Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beihang University, Xueyuan Road 37, Beijing, 100191, China.
School of Biological Science and Medical Engineering, Beihang University, Xueyuan Road 37, Beijing, 100191, China.
Int J Numer Method Biomed Eng. 2016 Jun;32(6). doi: 10.1002/cnm.2750. Epub 2015 Dec 3.
In contrast to numerous researches on static or quasi-static stiffness of cervical spine segments, very few investigations on their dynamic stiffness were published. Currently, scale factors and estimated coefficients were usually used in multi-body models for including viscoelastic properties and damping effects, meanwhile viscoelastic properties of some tissues were unavailable for establishing finite element models. Because dynamic stiffness of cervical spine segments in these models were difficult to validate because of lacking in experimental data, we tried to gain some insights on current modeling methods through studying dynamic stiffness differences between these models. A finite element model and a multi-body model of C6-C7 segment were developed through using available material data and typical modeling technologies. These two models were validated with quasi-static response data of the C6-C7 cervical spine segment. Dynamic stiffness differences were investigated through controlling motions of C6 vertebrae at different rates and then comparing their reaction forces or moments. Validation results showed that both the finite element model and the multi-body model could generate reasonable responses under quasi-static loads, but the finite element segment model exhibited more nonlinear characters. Dynamic response investigations indicated that dynamic stiffness of this finite element model might be underestimated because of the absence of dynamic stiffen effect and damping effects of annulus fibrous, while representation of these effects also need to be improved in current multi-body model. Copyright © 2015 John Wiley & Sons, Ltd.
与众多关于颈椎节段静态或准静态刚度的研究相比，关于其动态刚度的研究发表得很少。目前，多体模型中通常使用比例因子和估计系数来纳入粘弹性特性和阻尼效应，同时一些组织的粘弹性特性无法用于建立有限元模型。由于这些模型中颈椎节段的动态刚度因缺乏实验数据而难以验证，我们试图通过研究这些模型之间的动态刚度差异来深入了解当前的建模方法。通过使用可用的材料数据和典型的建模技术，开发了C6-C7节段的有限元模型和多体模型。这两个模型用C6-C7颈椎节段的准静态响应数据进行了验证。通过以不同速率控制C6椎体的运动，然后比较它们的反作用力或力矩，研究了动态刚度差异。验证结果表明，有限元模型和多体模型在准静态载荷下都能产生合理的响应，但有限元节段模型表现出更多的非线性特征。动态响应研究表明，由于纤维环的动态加强效应和阻尼效应的缺失，该有限元模型的动态刚度可能被低估，而在当前的多体模型中，这些效应的表示也需要改进。版权所有© 2015约翰威立父子有限公司。
