The seat frame to be applied to future autonomous vehicles is expected to be
rotatable considering various seating configurations. For the rotatable or
swivel seat frame, it might be more difficult to secure passenger-related safety
performances including seat belt anchorage (SBA) strength than a conventional
seat frame because the conventional seat frame has two seat belt anchoring
points on the body center pillar whereas those points of the swivel seat frame
should be all located within the rotating structures in the seat frame. Since
the swivel seat frame adds a structure for rotation, the mass of the swivel seat
frame significantly increases compared to the nonrotatable seat frame, which may
become an obstacle to reducing the mass of the vehicle. Currently, there are not
many cases of mass production of rotating vehicle seats, and there are hardly
any reports of mass reduction through advanced steel materials or corresponding
numerical safety performance. In this study, the mass of the swivel assembly,
the core part of the swivel seat frame, was reduced by more than 22.8% by
establishing a baseline model of the swivel seat frame through benchmarking,
applying advanced steel materials to it, and improving the structural design. In
addition, a swivel assembly concept with an improved structure for better safety
performance was derived, and the steel grade and gauge of the relevant core
parts were optimized using a commercial program LS-OPT and various libraries of
Python, an open-source programming language. The lightweight concepts and
various solutions derived from this study are expected to be a good starting
point for applying advanced steel grades to future seat frames.