Stress and fatigue life analyses of a five-piece rim and the proposed optimization with a two-piece rim

• Numerical modeling of multi-piece OTR wheels and tires.
• Highly detailed FE models of OTR wheel/tires.
• Numerical models validated to experimental findings.
• Wheel/tire assemblies tested and performance quantified.
• Fatigue life estimated and quantified.

A five-piece rim and a two-piece bolt-connected rim were investigated to examine stress levels and fatigue lives on critical regions. The finite element models of the rim/tire assemblies were developed and validated through tire engineering data and previously validated modelling approaches. The rim/tire assemblies were simulated under two conditions, (1) application of a 23,100 kg static load followed by a 24.14 km/h travelling speed and an 82° wheel angle, and (2) application of a 26,900 kg static load followed by an 8.05 km/h travelling speed and an 82° wheel angle. The results revealed that travelling and steering speeds were the key factors in causing high stresses and bolt tension forces. Compared to the five-piece rim, the two-piece rim decreased the maximum stresses by over 30% for both loading conditions; consequently the fatigue lives were increased by over two orders of magnitude. The maximum bolt forces for the two-piece rim were estimated to be 195,680 N and 111,360 N separately.