To optimize the ride comfort it is of special importance to know the possible vibration phenomena and eigenfrequencies of the subsystem "suspension". Therefore this study analyses the differences between the full vehicle test and tests on a dynamic suspension test rig. Especially the missing possibility of the deflection in longitudinal direction on a dynamic test rig restricts the investigation of a parameter analysis. Further on the simple assumption of a quarter model to describe the eigenfrequencies of a suspension are not enough. In cars with a very hard damper stiffness it is possible that eigenfrequencies evoke within the suspension. This reduces the ride comfort for the passenger. For a detail analysis of such phenomena a multi body simulation is indispensable. A stiff damper stiffness is necessary for a good ride performance. But the disadvantage of a high wheel trajectory angle is that the longitudinal eigenfrequency is visible in the vertical direction. The longitudinal stiffness of the suspension influences this vertical eigenfrequency. The frequency of this resonance is lower than the longitudinal eigenfrequency of the suspension. A stiff damper stiffness is responsible for this phenomenon. Furthermore this resonance frequency in vertical direction is influenced by the damper position. A proposal for an optimal damper stiffness characteristic was given to get an optimal dynamic transmission behaviour up to 30 Hz. The comparison between a real test and the simulation shows a good correlation. Further on a parameter study regarding low cd accelerations on driving over a bump was carried out. This study yields that the ride comfort of a suspension depends on the wheel trajectory angle, the damper position and the longitudinal elasticity. All of these parameters influence each other for the P2P (Peak-To-Peak) values in vertical and longitudinal direction. A high wheel trajectory angle, which is necessary for a good anti-squat, needs to achieve good ride comfort a much lower longitudinal elasticity than a lower wheel trajectory angle would do. In the future the results should be proved by analyses on a dynamic suspension test rig with a possible longitudinal excitation.


    Access

    Access via TIB

    Check availability in my library


    Export, share and cite



    Title :

    Comparability of dynamic chassis measurements with full vehicle tests using the example of a sports car


    Contributors:


    Publication date :

    2014


    Size :

    22 Seiten, Bilder, 14 Quellen


    Type of media :

    Conference paper


    Type of material :

    Print


    Language :

    English





    Comparability of dynamic chassis measurements with full vehicle tests using the example of a sports car

    Haberzettl,S. / Stein,W. / Weijenberg,N. et al. | Automotive engineering | 2014


    Vehicle Efficiency on Chassis Dynamometer Tests

    Villela, Antonio Carlos Scardini / Machado, Guilherme Bastos / Botero, Sergio William | SAE Technical Papers | 2014


    Racing and sports Car Chassis Design

    Costin, M. / Phipps, D. | TIBKAT | 1984


    Chassis efficiency tests

    North, O.D. | Engineering Index Backfile | 1922