Car manufacturing companies inside and outside the country, are continually improving their plans to present new models, so various investigations on different parts of automobiles are being done in order that all components could have a better function and interaction. Static and dynamic body analysis of automobiles is one of the solutions that is exploited to optimize current design. In between rollover test is one of the criteria used to determine body strength of the cars. In this dissertation using finite element method, ECE66 rollover standard is simulated on O457 bus and body deformation has been measured. Afterwards, as deformations in body were greater than standard level, suggestions have been aroused to increase body strength. Regarding available capabilities and limitations existed in producing process, the superstructure has been optimized. Finally data extracted from software, have qualitatively been compared with existed experimental results and their accuracy were verified.
