Modal Analysis of a Tubular Structure Vehicle Chassis

The structure of a vehicle is often excited by the powertrain and suspension systems. The modal analysis determines the mode shapes and the natural frequencies of each mode. These dynamics characteristics can be used for stiffness verification of different chassis regions. In this work the finite element method was used for the determination of the mode shapes of a tubular structure chassis. The computational results were compared qualitatively with experimental data obtained from vibration severity tests. The data obtained in the model was used to verify the dynamic design of the structure, avoiding high displacements in the shafts and in the vehicle habitacle. The improvements in the design results in more reliability of the powertrain and more comfort for the vehicle occupant.