CAE Analysis, Optimization and Fabrication of Formula SAE Vehicle Structure 2015-01-0072
Suspension and chassis play a vital role in the structural performance of a Formula SAE vehicle. This paper focuses on CAE modeling and simulation study of the FSAE vehicle structure to analyze and improve its characteristics; and also the fabrication of the structure. This has been done for the current vehicle prepared according to 2014 Formula SAE rules; as part of Thapar University (TU) Formula student team - Team Fateh.
The study started with Multi Body Dynamic (MBD) model building of front and rear suspension system using ADAMS/Car and Finite Element (FE) model building of space frame type chassis using HyperMesh for the current (2014) and previous (2011 and 2012) TU FSAE vehicles.
The MBD model was used for carrying out kinematic analysis (suspension wheel travel) to calculate and analyze the roll centers using Design of Experiments (DOE) study. The FE model was used for determination of mode shapes, natural frequencies and for calculating chassis stiffness; by carrying out the normal modes and linear static analysis. Further, the variation of torsion stiffness along length of chassis was also studied.
As roll center and torsion stiffness are the most important quantifiable aspects to the suspension and chassis (respectively) of a race car, their evaluation at subsystem level is essential to analyze the performance of the FSAE vehicle. Design changes were made in the 2014 vehicle structure to increase chassis torsion, lateral and vertical bending stiffness; and reduce suspension roll center movement. The improvement in current vehicle structure characteristics over previous ones has been summarized.
Further, the topology optimization carried out (using input loads from MBD analysis) on 2014 vehicle components like suspension uprights and chassis bulkhead and the resultant weight reduction has been described.
Finally, the fabrication of final design of the frame has been carried out and presented as part of TU FSAE 2014 vehicle structure development.