三种三维有限元建模方法在跟骨模型建立中的应用和比较

目的分析和比较不同三维有限元建模方法在生物组织模型建立过程中的应用。方法基于同组的序列CT图像,使用直接法、间接法和两种方法相结合的思路分别建立跟骨的三维有限元模型,并对3种模型在相同条件下进行简单加载计算。结果直接建模法生成的跟骨三维有限元模型具有31386个节点,115646个单元,间接法生成的跟骨三维有限元模型具有22832个节点和15403个单元。直接与问接结合的方法所得模型包括13050个节点和46654个单元。3个模型计算结果表现为应力分布规律基本相同,局部有差异,并在应力大小上有较大差异。结论模型表面的粗糙程度和材质赋予的形式对模型的计算结果有较大影响。不同建模方法具有不同的适用领域,为满足医学研究需求,认为两种方法的相互借鉴将推动计算生物力学的发展。

Comparative study on three different methods applied to establish 3D finite element calcaneus model

Objective To analyze and compare the application of different modeling methods used in the construction of bio-tissue 3D finite element model. Methods: Based on the same serial CT images, to construct calcaneus 3D finite element model with the implementing of three different methods (direct, indirect, and composite methods), then to carry out simple loading calculation on two models under the same condition. Results The number of nodes and elements generated from direct modeling are 31386 and 115646, while that from indirect modeling are 22832 and 15403, respectively; and that of composite method are 13050 and 46654, respectively. The results reveal the similar distributing of von Mises Stress of three models, with some local differences, but the special stress values show greater difference. Conclusion The exterior roughness of model and the form of material assignment have great effect on the calculating result of models. Different modeling method has their own appropriate application fields. For the purpose of medical research, it would be better to combine the two methods to promote the development of computational biomechanics.