Vehicle Seat Vibration Transmissibility Using Biodynamic Modelling

Nine linear discrete lumped parameter models are investigated to approximate a human beings dynamic response subjected to vertical seat vibration, ranging from two to seven degrees of freedom (DOF). Each model described has a unique biodynamic configuration that simulates the impedance and vibration transmissibility behaviour for different sections of the human body. A comparative study supported by published data is conducted for all nine models to distinguish the different groups of models that depict the seat to head transmissibility, seat-person transmissibility and mechanical impedance characteristics applied to vehicle seats for normal driving conditions. The 2, 3 and 4 DOF models are able to simulate both the discomfort levels experienced in the head and mechanical impedance behaviour. The seat-person transmissibility and discomfort in the lower torso, legs and thighs are best described using the 3 and 5 DOF models. A sensitivity analysis in respect of biodynamic stiffness and damping variations is performed to ascertain the resilience of applying each model to different vibration environments.