The vibration transmission characteristic of the seated human body under multi-axis vibration: A combined experimental and numerical simulation study

The vibration transmission characteristic is a critical evaluation metric for assessing seat vibration comfort. To accurately simulate and predict these characteristics within the seat-occupant coupling system (SoCS) and provide guidance for optimizing seating comfort design, a coupled multi-body human dynamics model and an advanced SoCS model are developed in this work. Firstly, experiments are conducted to determine the dynamic apparent mass (DAM) and vibration transmissibility of human subjects under the comprehensive excitation. Subsequently, these experimental data serve as the basis for calibrating the models. Additionally, the goodness-of-fit is applied to assess and quantify the agreement between simulation predictions and experimental outcomes. Finally, the sensitivity analysis of the validated models is performed to investigate the effect of critical parameters on vibration transmission characteristics. The findings demonstrate that: (1) the validated models exhibit exceptional precision and accuracy, effectively capturing the dynamic characteristics of the subject; (2) Vibrational energy delivered to the body can be significantly reduced by adjusting the vertical and lateral contact stiffness/damping of the key segments. (3) In practical engineering applications, seat vibration comfort can be improved through modifying the seat frame’s stiffness and altering the polyurethane foam’s material properties.