后碰撞中人体颈部动力学响应的有限元分析

FE ANLYSIS OF HUMAN NECK DYNAMIC RESPONSES UNDER REAR-END IMPACT

  • 摘要: 为了得到人体颈部在后碰撞中的动力学响应数据,细化完善了先前建立并验证的符合中国人特征且具有较高逼真度的C1-T1全颈椎有限元生物力学模型,模型由椎骨、椎间盘(髓核、纤维环及软骨终板)、韧带和肌肉构成,用六面体实体单元、梁单元和索单元进行模拟,其材料分别定义为线弹性、粘弹性和索。用后碰撞志愿者实验数据对模型进行仿真,得到各椎骨间相对转角,软组织的等效应力曲线。后碰撞过程中颈部形成S形曲线、C形曲线,各软组织应力曲线峰值均发生于最大S形曲线、C形曲线出现阶段,最大相对转角及各软组织最大应力主要发生在C7-T1。后碰撞中过度伸展易导致颈部损伤。有限元仿真有助于理解颈部运动学及其损伤机制。

     

    Abstract: A detailed three-dimensional finite element model of Chinese human neck developed previously is improved and used to investigate the dynamic responses under rear-end impact. The model is composed of the seven cervical vertebrae (C1-T1), the first thoracic vertebra (T1), the intervertebral discs (nucleus, annulus, endplates), ligaments and muscles. It includes eight-node solid elements, hughes-liu beam elements and two-node cable elements. The material properties are characterized by isotropic, viscoelastic and cable. The volunteer experimental data during rear-end impact is applied to the finite element model to obtain segmental rotational angle and von mises stress of soft tissues. The cervical S-shaped curve and C-shaped curve are predicted. Each level of soft tissues experiences the greatest stress at the time of maximum cervical S-shaped curve and C-shaped curve. The highest segmental angle and maximum stress mainly occur at C7-T1.The cervical spine is likely at the risk of hyperextension injuries during rear-end impact. The simulation of finite element models is helpful for the understanding of spinal kinematics and mechanisms of spinal injury.

     

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