A Bond Graph Approach to Analysis and Simulation of a Coupled Torsion Beam Axle

Coupled Torsion Beam Axles (CTBA) are combined with springs and dampers to form suspensions for compact automobiles. These are large metal components with complex geometries, presenting difficulty in estimating their influence on vehicle dynamics. Due to this complexity, the design process involves generating Finite Element Models (FEM) for analysis and global vehicle performance. However, FEM analyses are time-consuming. This paper presents, as an alternative approach, a low-order model for simulation developed from first principles. The model is simulated for common dynamic and static tire/axle deflection conditions and compared to real vehicle Suspension Parameter Measurement Device (SPMD) results. The trends of the dynamic model and actual vehicle test data are presented and compared.