MacLeod Alisdair R, Rose Hannah, Gill Harinderjit S
Centre for Biomechanics, Department of Mechanical Engineering, University of Bath, Bath BA2 7AY, UK e-mail:
J Biomech Eng. 2016 Dec 1;138(12). doi: 10.1115/1.4034653.
Synthetic biomechanical test specimens are frequently used for preclinical evaluation of implant performance, often in combination with numerical modeling, such as finite-element (FE) analysis. Commercial and freely available FE packages are widely used with three FE packages in particular gaining popularity: abaqus (Dassault Systèmes, Johnston, RI), ansys (ANSYS, Inc., Canonsburg, PA), and febio (University of Utah, Salt Lake City, UT). To the best of our knowledge, no study has yet made a comparison of these three commonly used solvers. Additionally, despite the femur being the most extensively studied bone in the body, no freely available validated model exists. The primary aim of the study was primarily to conduct a comparison of mesh convergence and strain prediction between the three solvers (abaqus, ansys, and febio) and to provide validated open-source models of a fourth-generation composite femur for use with all the three FE packages. Second, we evaluated the geometric variability around the femoral neck region of the composite femurs. Experimental testing was conducted using fourth-generation Sawbones® composite femurs instrumented with strain gauges at four locations. A generic FE model and four specimen-specific FE models were created from CT scans. The study found that the three solvers produced excellent agreement, with strain predictions being within an average of 3.0% for all the solvers (r2 > 0.99) and 1.4% for the two commercial codes. The average of the root mean squared error against the experimental results was 134.5% (r2 = 0.29) for the generic model and 13.8% (r2 = 0.96) for the specimen-specific models. It was found that composite femurs had variations in cortical thickness around the neck of the femur of up to 48.4%. For the first time, an experimentally validated, finite-element model of the femur is presented for use in three solvers. This model is freely available online along with all the supporting validation data.
合成生物力学测试样本经常用于植入物性能的临床前评估，通常与数值建模相结合，如有限元（FE）分析。商业和免费的有限元软件包被广泛使用，特别是有三个有限元软件包越来越受欢迎：Abaqus（达索系统公司，约翰斯顿，罗德岛州）、ANSYS（ANSYS公司，卡农斯堡，宾夕法尼亚州）和Febio（犹他大学，盐湖城，犹他州）。据我们所知，尚无研究对这三种常用求解器进行比较。此外，尽管股骨是人体中研究最广泛的骨骼，但不存在免费的经过验证的模型。该研究的主要目的首先是比较三种求解器（Abaqus、ANSYS和Febio）之间的网格收敛性和应变预测，并提供适用于所有这三个有限元软件包的第四代复合股骨的经过验证的开源模型。其次，我们评估了复合股骨股骨颈区域周围的几何变异性。使用在四个位置安装了应变片的第四代Sawbones®复合股骨进行实验测试。从CT扫描创建了一个通用有限元模型和四个特定样本有限元模型。研究发现，这三种求解器的结果高度一致，所有求解器的应变预测平均在3.0%以内（r2>0.99），两个商业代码的应变预测平均在1.4%以内。通用模型相对于实验结果的均方根误差平均值为134.5%（r2 = 0.29），特定样本模型为13.8%（r2 = 0.96）。研究发现，复合股骨在股骨颈周围的皮质厚度变化高达48.4%。首次提出了一个经过实验验证的股骨有限元模型，可用于三种求解器。该模型以及所有支持验证数据均可在网上免费获取。
