Extensive simulation enabled experts at Reverie to optimize the safety of its new Super Sport motorsport seat, before being sled tested
UK-based composite specialist Reverie is due to launch a new carbon fiber motorsport seat aimed at the FIA 8855 1999 safety standard. It features a unique optional bolt-on to the head restraint, which protects the driver’s head in case of a side impact. MD Simon Farren said, “That’s the worst case scenario because you’ve got the head and the helmet putting a big load into the head restraint, which puts a much bigger twisting force into the back of the seat.”
Development of the seat took approximately one year and focused on safety testing. Extensive dynamic simulation with Arup software was used to optimize the laminate of the seat, therefore helping to achieve the design team’s weight target of under 4kg. Virtual evaluation was also performed to prove that the head restraint concept worked as expected. “This gave us confidence that we could go into sled testing and be very near the mark first off,” noted Farren.
That dynamic stress analysis also enabled the team to identify areas of high stress on the seat. This is particularly important for carbon composite materials, which are not elastic and require a safety factor. Reported Farren, “We went back and optimized the shape of the seat in CAD to smooth out those areas. We also increased the sections between the front and rear skin (two shells that are bonded together) to drop those stress levels, and we reconsidered carefully fiber placement and ply overlap joints.”
Sled testing of the seat fitted with the head restraint bolt-on was conducted at TRL’s facility in the UK, at 20g rear, 15g side and 10g rear impacts. Initial test results did not correlate with the simulation so, using video footage supplied by TRL, Arup was able to adjust the virtual model and the Reverie design team was able to build a revised seat lay-up from the improved dynamic stress model. According to Farren, several prototypes were needed to achieve the optimum lay-up for the laminate, while keeping to the 4kg weight target.
Head restraint stress analysis in Arup software
Arup simulation of a 20g rear impact sled test
Physical sled testing of the seat at TRL’s facility