模拟车载乘员撞击上颌骨损伤的有限元研究

目的：建立具有牛物力学特性的动态颅面骨三维有限元模型，在上颌骨正面撞击时响应过程，探讨颅面骨外伤骨折的牛物力学基础。方法：采用GE Lightspeed多层螺旋CT对一例老年无牙颌患者从头顶到下颔骨下缘CT扫描，三维影像重建，数据转换，运用自编程序和Nastran软件相结合方法，模仿汽车乘员在年内约束系统下撞击上颌骨正面。结果：获得颅面骨三维有限元牛物医学模型，分析化正面撞击时颅而骨各部位应力改变。当着力点位丁上颌骨，应力沿上颌骨、翼突、颧骨向颞骨颅底传导，同样也会影响颢下颌关节，髁突及髁突颈部应力有明显改变，骨结构的横截而积陡然减小的区域出现应力集中。撞击波呈梯度向后传导，在寰枕关节处应力集中，明显变化。结论：撞击波造成各部分应力改变会在骨缝连接处和骨关节处集中，出现传导改变和传导中断，肜成较强大的应力梯度，游离端出现应力回弹，相应的张应力、剪应力易导敛骨折的发小。而此处即为损害较严重的区域。撞击点处，要为压缩破坏，撞击点背面的骨组织为拉伸破坏，髁突等游离端主要为拉伸破坏，从理论上，这可能足撞击损伤的小物力学机理之一。

The simulation and analysis of the impact injury of persons in cars with finite element methods

Objective: To analyze biomechanics of impact injury, in the condition of the simulate impact on maxillary rejoins in accident. Method: The complex cranial geometry was measured from a series of two-dimensional CT images. The multy-lay spiral CT scans were transformed with a self-developed preprocessor into a finite element mesh. Identical impact and boundary conditions were used for the maxillary impact simulations. Results: The higher stress was showed in the nasal-maxilla rejoins and atlas occipital articular in 3d FEM. Conclusions: The concentration of stress and tension stress were might the thought to be one of the main biomechanical mechanism of impact injury. The FEM is helpful to analyze biomechanics of skull impact injury.