Topological optimisation design of passenger car seat backrest frame based on multiple-loading conditions

The newly revised national standard GB 13057-2014 ‘The strength of the seats and their anchorages of passenger vehicles’ puts forward higher requirements for occupant protection of passenger car seats in the dynamic test. Simply improving safety performance may increase seat weight. Considering the dual requirements of safety performance and light weight, this article adopted the topology optimisation method and took into account the strength requirements of multiple loading conditions: forward loading and rearward loading, and finally optimised the structure of seat backrest frame. By changing the weight ratio of loading conditions and the topological mass fraction, the optimal material distribution and force transmission paths of seat backrest frame were optimised. At the same time, considering the ergonomics and the strength of the seat fixing points, the structure of seat backrest frame was fully optimised. On the premise of improving the safety performance of the seats (occupant protection), significant weight reduction was also achieved.