【摘要】 目的利用多柔体动力学方法,分析Herbst机动飞行时腰椎肌肉-骨骼系统内力变化,探讨载荷下飞行员腰椎间盘力学损伤机制。方法基于腰椎肌肉-骨骼系统多体动力学模型,施加Herbst机动飞行产生的三轴时变过载,仿真计算3种腰椎运动与飞行过载耦合工况,根据腰椎间盘内力、小关节接触力、肌肉及韧带应力水平,评价飞行载荷导致的力学变化。结果腰椎前屈与Herbst机头-足向过载耦合产生了椎间盘峰值内力最大值,这说明在过载过程中的腰椎前屈更容易损伤腰椎椎间盘,尤以L5-S1间盘最为明显,而腰椎伸展可以明显减小下腰椎负载,过载引发椎体间相对滑移,增大腰椎间盘剪切载荷与关节接触力,引起肌肉与韧带内力变化。结论多体动力学方法可以仿真计算腰椎肌肉-骨骼系统应力变化,为解释飞行中腰椎间盘疲劳损伤机理提供理论依据与数据支撑。更多还原

【Abstract】 Objective To investigate the internal dynamic change of the biological structure of human lumbar spines using multibody dynamics method, and to find out more about the spinal degeneration process under flight overload conditions. Methods Based on a detailed multibody model of human lumbar spines, flight overload–time curves in Herbst maneuver were applied on the model spine. The internal force level of intervertebral discs, contact force of apophyseal joints, and muscle-tendon forces were calculated. Results The peak internal intervertebral force was generated by coupling between lumbar spine flexion and pilot seat normal overload, and lumbar spine pre-extension could obviously reduce the lower back load. Flight overload could induce dynamic shear displacement between vertebral bodies, leading to the changes of the intervertebral disc shear force and contact force in apophyseal joints. As a result, muscle-tendon forces became unstable. Conclusion Multibody dynamics approach can present the internal dynamics of the intervertebral disc. Consequently, it can potentially be used as a novel method to theoretically explain the lumbar fatigue mechanism during flight overload.更多还原