Requirements for comparing the performance of finite element models of biological structures
Requirements for comparing the performance of finite element models of biological structures
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DOI：
10.1016/j.jtbi.2008.08.017
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发表时间：
2009-01-07
影响因子：
2
通讯作者：
Slater, G. J.
中科院分区：
文献类型：
--
作者：
Dumont, E. R.;Grosse, I. R.;Slater, G. J.
三维成像和计算能力的广泛应用促使越来越多的生物学家使用有限元分析 (FEA) 来研究活体和灭绝生物体的机械功能。比较有限元模型的研究不可避免地兴起，这就提出了两个关键问题：如何能够并且应该进行这种比较分析：（1）什么指标适合使用有限元模型评估生物结构的性能？ (2) 如何比较性能以消除尺寸和形状的影响？就性能而言，我们认为能量效率是生物结构的合理最优标准，并且我们证明总应变能（使结构变形所消耗的功的量度）是比较用有限元建模的结构的机械效率的稳健指标。当模型输入参数（肌肉力、详细的材料特性）和/或输出参数（反作用力、应变）通过活体动物的研究得到充分记录时，可以充满信心地解释有限元分析的结果。然而，许多研究人员希望比较难以或不可能获取这些输入和验证数据的物种。在这些情况下，如果尺寸变化受到控制，研究人员仍然可以比较形状不同的结构的性能。我们提供了一个理论框架和经验数据，证明将有限元模型缩放到相等的力：表面积比可以消除模型尺寸的影响，并提供仅基于形状的应力强度性能的比较。缩放为具有相等的施加力：体积比的模型为应变能比较提供了基础。因此，尽管生物结构的有限元分析应尽可能通过实验进行验证，但本研究表明，只要适当缩放，就可以比较未经验证模型的相对性能。 (C) 2008 Elsevier Ltd. 保留所有权利。
The widespread availability of three-dimensional imaging and computational power has fostered a rapid increase in the number of biologists using finite element analysis (FEA) to investigate the mechanical function of living and extinct organisms. The inevitable rise of studies that compare finite element models brings to the fore two critical questions about how such comparative analyses can and should be conducted: (1) what metrics are appropriate for assessing the performance of biological structures using finite element modeling? and, (2) how can performance be compared such that the effects of size and shape are disentangled? With respect to performance, we argue that energy efficiency is a reasonable optimality criterion for biological structures and we show that the total strain energy (a measure of work expended deforming a structure) is a robust metric for comparing the mechanical efficiency of structures modeled with finite elements. Results of finite element analyses can be interpreted with confidence when model input parameters (muscle forces, detailed material properties) and/or output parameters (reaction forces, strains) are well-documented by studies of living animals.However, many researchers wish to compare species for which these input and validation data are difficult or impossible to acquire. In these cases, researchers can still compare the performance of structures that differ in shape if variation in size is controlled. We offer a theoretical framework and empirical data demonstrating that scaling finite element models to equal force: surface area ratios removes the effects of model size and provides a comparison of stress-strength performance based solely on shape.Further. models scaled to have equal applied force:volume ratios provide the basis for strain energy comparison. Thus, although finite element analyses of biological structures should be validated experimentally whenever possible, this study demonstrates that the relative performance of unvalidated models can be compared so long as they are scaled properly. (C) 2008 Elsevier Ltd. All rights reserved.