An Approach for Validation of Suspension Seat for Ride Comfort using Multi-Body Dynamics

The seat of a class-8 commercial vehicle in North America consists of a seat-suspension system to reduce the vibrations transmitted to the seat occupant from the cab floor. The vibration isolation provided by the suspension of the seat determines the ride comfort experienced by the occupant. Until now, the vibration isolation provided by the suspension seat was evaluated by exciting the seat on a Six-Axis shaker table with different displacement profiles. This paper presents the development of a validated Multi-Body Dynamics (MBD) model that can be used to assess the ride comfort of a given suspension seat. The model was validated using the data generated during testing of a prototyped suspension seat. The vibration transmissibility predicted by the model was compared with that of test data and it was observed that they correlated by about 80%. The development of this model will significantly reduce the amount of testing needed which can further condense the product development time. Also, as the model can be built from 3D solid Geometries, the ride comfort provided by the seat can be evaluated early in the design process. This enables the design team to modify the suspension seat design early in the design process, thus eliminating the need to make time and resource consuming design changes at later stage.