Seating dynamics, and specifically the human perception of the dynamic comfort of a seat, is an area that is of increasing importance to automotive manufacturers catering for a market becoming more and more competitive and sophisticated. A major portion of the vibration decided to evaluate the vibration by concentrating their attention on the vertical component at the seat top, as it was the most prominent. The Seat Effective Amplitude Transmissibility (SEAT) value is the ratio of the vibration experienced on top of the seal and the vibration that one would be exposed to when sitting directly on the vibrating floor. SEAT values have been widely used to determine the vibration isolation efficiency of a seal. In this article the subjective evaluations of six persons were compared to the SEAT values estimated from experimentally obtained transmissibility curves for 16 different automobile seals ranging from sedans to SUVs and pickups. A vertical rough road stimulus was used as input for both the subjective testing and the SEAT calculations. The SEAT values were estimated using the power spectral density of the vertical vibration input at the seal track and the measured transmissibility data to compute the response in the vertical direction at the seal top. The averaged, estimated SEAT values were compared to averaged measured values and significant correlation (R2 = 0.94) was obtained. The subjective ratings were obtained on the Ford Vehicle Vibration Simulator using a paired comparison methodology that eliminated static comfort bias during the evaluation. The results indicated that there is good correlation (R2 = 0.94) between the subjective ratings and the SEAT values when the subjective ratings and transmissibilities are averaged over the six subjects. This means that it may be useful and possible to set targets for seat design using SEAT values. However, it is important to realize what the limitations of this research are. Achievement of a correlation coefficient of R2 = 0.94 was only possible by paying attention to a number of key details, and the result is still only known to apply to rough road stimuli, which in practice means stimuli whose energy is concentrated around the wheel hop frequency of the vehicle, or about 12-16 Hz. The key details include careful measurement of the transmissibility on a shaker system that is rated for human subjects, the use of a broadband stimulus for this measurement which is similar in amplitude to the road excitation targeted, the use of a large enough and diverse enough jury of human subjects to make the transmissibility measurements, and the availability of a vibration measurement at the seat track which is representative of the vehicle that the seat is designed for.


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    Title :

    The use of seat effective amplitude transmissibility (SEAT) values to predict dynamic seat comfort


    Additional title:

    Die Verwendung von 'Seat Effective Amplitude-Transmissibility'-Werten zur Vorhersage des dynamischen Komforts von PKW-Sitzen


    Contributors:

    Published in:

    Publication date :

    2003


    Size :

    22 Seiten, 11 Bilder, 5 Tabellen, 20 Quellen




    Type of media :

    Article (Journal)


    Type of material :

    Print


    Language :

    English