Measurement of the distributed dynamic stiffness of seats under compression to analyze dynamic characteristic of seats

Supporting stiffness of seats is an important component affecting dynamic characteristics cognized by a passenger. To analyze dynamic characteristic of a seat for vehicles operating on various road conditions, the seat vibration from road irregularity should be understood and compared. In this study, the seat is analyzed as distributed supporting system. The dynamic stiffness is measured using masses on elastic foundation. The deflection of the seat under compression is analyzed using simple numerical model and used in understanding dynamic coupling between arrayed masses. The characteristic of the seats is analyzed by measuring distributed dynamic stiffness. The influence of seat cover, elastic support and flexible polyurethane foam on the measured stiffness was analyzed. The equivalent dynamic stiffness when larger dummy model is used in measurements is compared to the distributed stiffnesses