4. CHASSIS STRUCTURAL ANALYSIS
In designing Perodua Eco Challenge car, there are three load cases that are required to
be analysed to determine the car chassis rigidity, which is static bending, torsion and
rollover condition. Finite element analysis using CATIA V5 Generative Structural
Analsyis module was used to analyze the structural performance of the chassis. 3D
geometry model of the chassis structure was also used in performing the analysis to
enable better visualization of the final results.
For the static bending analysis, the total load acting on the chassis structure is assumed
to be 450kg or approximately 4500N. This is based on worst case condition where the
maximum allowable car weight as per stated in the Perodua Eco-Challenge 2011 design regulations is 450kg. While for rollover analysis, the maximum load is exerted
on the upper chassis structure where the required value is four times the maximum car
weight, which is approximately 18,000N as per stated in the Perodua Eco-Challenge
2011 design regulations Finally for the torsion analysis, the chassis torsional stiffness is
determined by assuming that the weight distribution on the car is 40:60, due to the car
is designed as a rear engine car with rear wheel drive, thus most of the car components
will be located at the car rear section. Thus, the load exerted on the chassis rear section
is approximately 1350N while for the front section, the load is approximately 900N.
The torsional stiffness of the chassis is calculated using equation 1 below