Ruoxun Fan, Jie Liu, Jun Liu, Weijun Wang
Department of Automotive Engineering, Jilin Institute of Chemical Technology, Jilin 132022, China.
No. 2 Hospital of Jilin University, Jilin University, Changchun 130025, China.
Appl Bionics Biomech. 2019 Jan 2;2019:5473891. doi: 10.1155/2019/5473891. eCollection 2019.
Occurring resonance may negatively affect the health of the human lumbar spine. Hence, vibration generated in working and living environments should be optimized to avoid resonance when identifying the natural frequency of the human lumbar spine. The range of the natural frequency of the human lumbar spine has been investigated, but its specific numerical value has not been determined yet. This study aimed at presenting an approach based on resonance for predicting the specific numerical value of the natural frequency of the human lumbar spine. The changes in the numerical fluctuation amplitudes and the cycles of lumbar mechanical parameters during resonance are greater than those during nonresonant vibration. Given that the range of the natural frequency has been identified, vibrations at different excitation frequencies within this range can be applied in a human lumbar finite element model for dynamic finite element analysis. When the excitation frequency is close to the natural frequency, resonance occurs, causing great changes in the numerical fluctuation amplitudes and the cycles of lumbar mechanical parameters. Therefore, the natural frequency of the lumbar finite element model could be back-calculated. Results showed that the natural frequency of the established model was 3.5 Hz. Meanwhile, the closer the excitation frequency was to the natural frequency, the greater the changes in the numerical fluctuation amplitudes and cycles in the parameters would be. This study presented an approach for predicting the specific numerical value of the natural frequency of the human lumbar spine. Identifying the natural frequency assists in finding preventive measures for lumbar injury caused by vibration and in designing the vibration source in working and living environments to avoid approximating to the natural frequency of the human lumbar spine.
发生共振可能会对人体腰椎健康产生负面影响。因此，在确定人体腰椎固有频率时，应优化工作和生活环境中产生的振动，以避免共振。虽然已经对人体腰椎固有频率的范围进行了研究，但其具体数值尚未确定。本研究旨在提出一种基于共振的方法来预测人体腰椎固有频率的具体数值。共振期间腰椎力学参数的数值波动幅度和周期变化大于非共振振动期间的变化。鉴于已确定固有频率范围，可将该范围内不同激励频率的振动应用于人体腰椎有限元模型进行动态有限元分析。当激励频率接近固有频率时，会发生共振，导致腰椎力学参数的数值波动幅度和周期发生巨大变化。因此，可以反算出腰椎有限元模型的固有频率。结果表明，所建立模型的固有频率为3.5Hz。同时，激励频率越接近固有频率，参数的数值波动幅度和周期变化就越大。本研究提出了一种预测人体腰椎固有频率具体数值的方法。确定固有频率有助于找到预防振动引起的腰部损伤的措施，并有助于设计工作和生活环境中的振动源，以避免接近人体腰椎的固有频率。
