Durability Prediction of Rear Engine Bus Using Virtual Proving Ground Road Loads

Strength and durability of commercial vehicle structure is of prime importance to users while quicker time to market and least material cost are demands of competitive world. This requires assessment not just with simplistic loadcases but robust and accurate predictions closely co-relating real proving ground conditions. This paper demonstrates systematic approach of first road load predictions using MBD model, then stress analysis using FE model and finally life prediction using fatigue solver.

MBD model was built using flex body, air suspensions with rigid links and tires with FTire characteristics. Same model ran on various virtual proving grounds and load history at various joints were extracted. Then inertia relief stress analysis with unit loads were carried out in Nastran and output stresses were mapped against load history in fatigue solver. Fatigue analysis was carried out using precise material's fatigue characteristic values and solver parameters for accurate durability prediction.