基于CAD技术的个体化下颌骨正交各向异性有限元模型的建立

目的 建立个体化下颌骨正交各向异性三维有限元模型.方法 利用CT薄层扫描下颌骨获取的断层图像数据,在自主开发的USIS软件的基础上,自动分辨骨皮质和骨松质轮廓边界,并对下颌骨采用非种子区域分割、非平行最佳切割曲面及B样条曲线拟合法一系列新型CAD方法进行人机对话自动重建精确的几何表面模型.定义结构材料参数后划分网格,并导入有限元计算软件ANSYS9.0中完成三维有限元建模.结果 建立了结构精确的个体化下颌骨正交各向异性的三维有限元模型.结论 基于CT数据和USIS软件的新型CAD方法实现了个体化下颌骨正交各向异性三维有限元模型的建立.

Establishment of Orthotropic Finite Element Model for Individual Mandible with CAD Technique

Objective To develope orthotropic three-dimensional (3 D) finite element model of individual mandible. Methods Based on thin layer CT mandible image data and the USIS software by ourselves, the individual geometry of the complete range of mandible was well established, also the distinction between the contour boundary of cortical and cancellous bones was done automatically. A series of new effective CAD methods such as no-seed region segmentation ,non-parallelbest cross-section planes and the algorithm employed a pair of B-spline curves fitting were used to accurately construct of 3D geometry surface model of the complete range of mandible in a man-machine conversation and automatic style. The elastic material properties were definited and the volumes were meshed with solid elements. The surface model was then imported into the FE software system ANSYS 9. 0 for the three-dimensional FE mesh construction. Results The orthotropic 3D finite element model of individual mandible with accurate anatomy and well simulated biomechanics was established. Conclusion With new CAD method based on CT data and USIS software the establishment of orthotropic 3D finite element model for individual mandible is realized.