Abstract: In order to have newly produced bus seats meet mandatory requirements of dynamic testing regulation GB13057-2014, a 3D mathematical model and finite element model of bus seats for a company was established by adopting explicit finite element software LS-DYNA 3D. And through coupling it with Hybrid III 50% male dummy model, a dynamic simulation model of seats was obtained. Then, test results were analyzed and simulation model was verified by using occupants' injury peak, WIC, dynamic responses and posture, and deformation mode of seats. Finally, the model was improved by changing sponge stiffness of seat back and light-weight seat foot design based on cost considerations. The results show that occupants' injury index and seat deformation are in good agreement in test and simulation, and error of WIC value is less than 4.3%. Moreover, light-weight design has obvious effects as seat foot weight reduces 31.8% and WIC value decreases 11% in case of an increase of 2.8% in cost. Weakening main components' strength and reducing sponge stiffness of seat back can effectively decrease occupants' injury level in rear seats on the basis of considering international acceptance standard of deformation range and seat comfort.

Key words: bus seat, dynamic test, simulation model, weighted injury criteria (WIC), cost consideration