As an essential part of a competitive solar powered car, the rollbar ensures the safety of the driver in the event of the car overturning. The video below shows the analysis of a composite rollbar with a specific requirement to withstand a 5G longitudinal loading applied to the top of the rollbar.
Stiffeners were added to the rear of the rollbar and the improvement in strength can clearly be seen from the video, where the failure index is compared between the original design and the modified rollbar design.
The modification was implemented in time for the car to be shipped for the upcoming event keeping the sponsors and team in the game.
The picture below shows the supporting structure that was added behind the seat. Material was also removed from the back of the rollbar in order for the modification not to increase the weight of the car. Also shown is the original moulded carbon fibre rollbar.
Moulded Carbon Fibre Rollbar
Weight Saving and Handling
Further analysis work was completed that investigated how much material could be removed from the centrebox portion of the car. The driving parameter was to minimise mass whilst ensuring that the cars torsional stiffness remained above a minimum value. Maintaining a minimum torsional stiffness ensures the cars handling and performance during cornering.
The video below shows the car twisting under torsion. The triangular areas of removed material can also be seen.