High strength steel keeps passengers in place

Designers of the centre seat assembly on Volvo’s new XC90 vehicle have solved their initial weight and safety problems by using an alternative material for the securing beam, high strength steel. The new sports utility vehicle seats seven passengers and the beam supporting the central seats has to be capable of withstanding collision forces of up to 6 tonnes. The problem is that the central seat frame needs to fold forwards and so cannot be fixed to the sides of the vehicle. The design firm tasked with solving this was Finnveden. The original beam design was in steel but weighed 22kg, 2kg heavier than the maximum weight that could be considered. It also failed to meet the post-collision bending limit of 20mm. Finnveden therefore turned to Docol high strength steel from SSAB Swedish Steel. The weight of the beam was reduced to 16.4kg and met the safety collision criteria.