Abstract
To increase the speed of vehicle development and to reduce the development
cost, computer aided analysis called CAE is applying more and more in the various field like
crash safety, aerodynamics, noise and vibration, ride and handling and so on. CAE application
for body durability is also important in the development phase especially on which test
vehicle is not available. Body durability analysis consists on two steps of simulation. One is
the road load prediction on rough road, which is predicted by multi body simulation (MBS).
The other is the fatigue life prediction with finite element analysis. However, the accuracy of
these simulations are not enough to estimate directly, so that the prediction is generally done
relatively with predecessor vehicle and mule car.
Focusing on road load prediction, one of the effective MBS approaches is the technique of the
back calculation. This technique generates the input on tire contact point to ground (called
effective road profile) from measurement data of predecessor vehicle response like sprung
acceleration, spindle force and so on. Here, the transfer function between these measuring
points and tire contact point are used for this back calculation technique.
This paper shows the study of this back calculation technique to improve the load road
prediction accuracy. The result shows that modelling error have influence to effective road
profile and prediction accuracy. And improvement was achieved by selecting sprung
acceleration and spindle force as a target signal for back calculation.
Keywords: Durability, Simulation, Road-Load Prediction