Li Zuoping, Alonso Jorge E, Kim Jong-Eun, Davidson James S, Etheridge Brandon S, Eberhardt Alan W
Department of Biomedical Engineering, University of Alabama at Birmingham, 1075 13th Street South, Hoehn 370, Birmingham, AL 35294, USA.
Ann Biomed Eng. 2006 Sep;34(9):1452-62. doi: 10.1007/s10439-006-9145-1. Epub 2006 Aug 9.
Three-dimensional finite element (FE) models of human pubic symphyses were constructed from computed tomography image data of one male and one female cadaver pelvis. The pubic bones, interpubic fibrocartilaginous disc and four pubic ligaments were segmented semi-automatically and meshed with hexahedral elements using automatic mesh generation schemes. A two-term viscoelastic Prony series, determined by curve fitting results of compressive creep experiments, was used to model the rate-dependent effects of the interpubic disc and the pubic ligaments. Three-parameter Mooney-Rivlin material coefficients were calculated for the discs using a heuristic FE approach based on average experimental joint compression data. Similarly, a transversely isotropic hyperelastic material model was applied to the ligaments to capture average tensile responses. Linear elastic isotropic properties were assigned to bone. The applicability of the resulting models was tested in bending simulations in four directions and in tensile tests of varying load rates. The model-predicted results correlated reasonably with the joint bending stiffnesses and rate-dependent tensile responses measured in experiments, supporting the validity of the estimated material coefficients and overall modeling approach. This study represents an important and necessary step in the eventual development of biofidelic pelvis models to investigate symphysis response under high-energy impact conditions, such as motor vehicle collisions.
利用一名男性和一名女性尸体骨盆的计算机断层扫描图像数据构建了人类耻骨联合的三维有限元（FE）模型。耻骨、耻骨间纤维软骨盘和四条耻骨韧带通过半自动分割，并使用自动网格生成方案用六面体单元进行网格划分。通过压缩蠕变实验的曲线拟合结果确定的双项粘弹性Prony级数，用于模拟耻骨间盘和耻骨韧带的速率依赖性效应。使用基于平均实验关节压缩数据的启发式有限元方法计算椎间盘的三参数Mooney-Rivlin材料系数。同样，将横向各向同性超弹性材料模型应用于韧带以捕捉平均拉伸响应。将线弹性各向同性特性赋予骨骼。在四个方向的弯曲模拟和不同加载速率的拉伸试验中测试了所得模型的适用性。模型预测结果与实验中测量的关节弯曲刚度和速率依赖性拉伸响应合理相关，支持了估计材料系数和整体建模方法的有效性。这项研究是最终开发生物逼真骨盆模型以研究高能冲击条件下（如机动车碰撞）耻骨联合响应的重要且必要的一步。
