Bremar Automotion's Use of Altair RADIOSS for Roll Cage Design & Certification

Bremar Automotion is an engineering design company based in Melbourne, Australia. They specialize in simulation, testing, validation, and optimization of designs using Computer Aided Engineering (CAE) across a range of industries such as automotive, truck & trailer, mining, industrial equipment, and motorsport. Bremar Automotion was recently granted approval from CAMS and the FIA to certify motorsport roll cages using Finite Element Analysis (FEA). This prestigious certification, granted only to approved bodies that are on the FIA’s technical list No. 35, enables Bremar to independently homologate motorsport roll cages using FEA both in Australia and internationally.

Bremar Automotion, an engineering design company based in Melbourne, Australia, was faced with the challenge of confirming the accuracy of their computer modeling with physical testing of a full-size roll cage. This was a prerequisite to gain accreditation by the Confederation of Australian Motor Sport (CAMS) and the Federation Internationale de’l Automobile (FIA). The roll cage, a crucial safety feature in any racecar, is designed to protect the driver in the event of an accident, particularly one that involves rollover of the vehicle. In many vehicles, the roll cage also forms the main structure of the chassis and they can often be a complex compromise between stiffness, safety, weight, and cost. As part of their accreditation process, Bremar Automotion was required to construct and test a full-size roll cage by applying the FIA’s specified roll cage loads to the structure. Destructive testing was required to confirm the accuracy of their computer modeling and to demonstrate competency to the FIA.

Bremar Automotion used Altair's RADIOSS for nonlinear finite element analysis. The roll cage used for the physical tests was designed by Bremar to result in a notable amount of plastic deformation of the structure under the applied loads. This required a nonlinear, high-displacement, and plastic deformation FEA analysis. Since Bremar engineers were already experienced users of Altair’s HyperWorks products, RADIOSS was the obvious choice for the nonlinear analysis requirements of this project. They began by designing a mild steel roll cage to suit the test rig, which was loosely based around a medium-sized vehicle weighing approximately 1200kg. The FIA load required on the main roll hoop was in the order of 10T. Once the FIA load criteria had been met, they also ran another test on the main hoop where they applied the maximum allowable displacement of 50mm, which required a load well in excess of 20T. The roll cage was instrumented with multiple sensors and strain gauges in order to measure deflection and strain at various locations on the structure and allow correlation with the FEA model.

• The results from the physical test compared with the FEA results using RADIOSS demonstrated the close correlation between the physical test and the computer model. This was very reassuring for Bremar Automotion, as it confirmed the accuracy of their simulation methods and the RADIOSS software. The tests performed on the motorsport roll cage were above and beyond those required for the FIA accreditation, which helped Bremar achieve a higher degree of confidence in their process. The test schedule also included a similar range of physical tests conducted on large Rollover Protection Systems (ROPS), as used on trucks, tractors, and earthmoving machinery. Good correlation was achieved for these tests as well, again confirming the accuracy of Bremar’s simulation methods and the RADIOSS software.

• Greater safety of roll cage with reduced weight
• High degree of confidence in approval process
• Successful correlation between physical test and computer model