An Integrated Approach for an Articulated Bus Development. Durability and Dynamics Simulations

This paper describes the application of structural and dynamic analysis of a new articulated bus developed by Daimler-Chrysler do Brasil. Structural analysis is carried out using both static and dynamic finite element analysis. The simulation of the vehicle running on a road track gives input for structural dynamic analysis that is followed by durability calculation. Dynamics analyses are carried out using the multibody dynamic methodology and the software Adams/View. Initially, a detailed numerical model is developed, including all the major non-linearities of the actual vehicle, such as air spring and shock absorber curves, suspension bump stops and tire model. Also the representation of the suspension geometry and articulation properties is introduced. Using this model, the first dynamic analysis performed is the calculation of forces acting on suspension elements when the bus is running on a road track with severe profile. Handling analysis of the articulated bus is then conducted, presenting the following simulations: bus at constant speed on steady-state curves, single lane change and sweep steer. Following, a braking analysis is done, aiming at choosing the best brake configuration for safe operation. The results of these analyses provide a very confident picture of the behavior of this vehicle, prior to the execution of tests with an actual prototype, giving directions for project improvements during its development.