Ride comfort of the driver/occupant of a vehicle has been usually analyzed by multibody biodynamic models of human beings. Accurate modeling of critical segments of the human body, e.g. the spine requires these models to have a very high number of segments. The resultant increase in degrees of freedom makes these models difficult to analyze and not able to provide certain details such as seat pressure distribution, the effect of cushion shapes, material, etc. This work presents a finite element based model of a human being seated in a vehicle in which the spine has been modelled in 3-D. It consists of cervical to coccyx vertebrae, ligaments, and discs and has been validated against modal frequencies reported in the literature. It was then subjected to sinusoidal vertical RMS acceleration of 0.1 g for mimicking road induced vibration. The dynamic characteristics of the human body were studied in terms of the seat to head transmissibility and intervertebral disc pressure. The effect of the seat pan angle on these parameters was studied and it was established that the optimum angle should lie between 15 and 19 degrees. This work is expected to be followed up by more simulations of this nature to study other human body comfort and seat design related parameters leading to optimized seat designs for various ride conditions.

翻译：车辆驾驶员/乘客的乘坐舒适性通常通过人体多体生物动力学模型进行分析。对人体关键部位（如脊柱）的精确建模需要极高数量的节段单元，由此产生的自由度增加使得模型分析困难，且无法提供座椅压力分布、坐垫形状与材料影响等细节。本研究建立了基于有限元方法的车内乘员模型，其中脊柱采用三维建模，包含颈椎至尾椎的椎骨、韧带及椎间盘，并通过文献报道的模态频率进行了验证。随后对模型施加0.1g正弦垂直均方根加速度以模拟道路引起的振动，从座椅到头部的传递函数及椎间盘压力角度研究了人体动力学特性。通过分析座椅倾角对这些参数的影响，确定最优倾角范围为15至19度。预计后续将通过更多此类仿真研究其他人体舒适度及座椅设计相关参数，从而针对不同行驶工况优化座椅设计。