Roll cage design and validation for a rally vehicle

The roll cage represents one of the most significant equipments for the personal protection in every sport car and in rally vehicles in particular. It is generally made of thin gauge pipes, joined together, to assemble a safety structure. This frame has to be designed in the way to absorb the kinetic energy during impacts reducing the risk of injuries for drivers and navigators. The design of an appropriate roll cage to be installed on a rally vehicle and its validation by Finite Elements methods represent the main motivation for this investigation. CAD frame was modelled by CATIA software using shell elements. Geometrical and material nonlinear FEM analysis was implemented by PAK code. Using experimental tests in displacement control conditions, critical forces on the structure were also determined. Numerical results were compared with experimental ones, permitting to refine the simulation model. Then, FEM provided the safety factor and all the information regarding the strength of acceptable materials. The CAD/FEM procedure, limiting the number of experimental tests, reduced cost and time requested for the design validation.