Research on fatigue life prediction and optimization of straddle type monorail vehicle running tire based on RSM

Material interface delamination exists in the running tires of straddle-type monorail vehicles during operation. To effectively enhance the safety and service life of Running Tires while reducing maintenance costs, this study establishes a finite element model of the straddle-type monorail vehicle Running Tire. Through stress and strain analysis under three working conditions (steady-state rolling, sideslip, and camber), combined with the Lake-Lindley model and maximum tearing energy method for fatigue parameter fitting, the fatigue life of Running Tires under multi-condition operation was simulated using Fe-safe software. The research findings indicate that the tread grooves and steel belt ends are high-risk areas under steady rolling conditions, with increased load significantly shortening lifespan. Fatigue damage occurs at the carcass rubber turnover points under sideslip conditions, and at the tread camber ends and apex rubber areas under camber conditions. With Running Tire fatigue life as the optimization target and steel belt angle as the design variable, parameter optimization of Running Tire steel belt angles was conducted using response surface methodology and genetic immune algorithm. The results demonstrate that optimized steel belt angles improve Running Tire fatigue life by 11.68%. This research provides theoretical foundations and methodological support for structural optimization design of straddle-type monorail vehicle Running Tires.