Thermo-Mechanical Fatigue Life Prediction of an Off-Road Mining Truck Tire

Mining truck tires are required to support heavy machine loads under rugged terrain and adverse ambient conditions for long operating times. High temperatures resulting from the thermo-viscoelastic coupling mechanism of the rubber materials speed up the fatigue strength reduction processes in dump truck tire. Typical tire fatigue failures include belt-edge separation, ply turn-up separation, and tread base and sidewall cracking. This work presents a novel approach for evaluating ultra-large mining truck tire component fatigue life using a thermal-mechanical duty cycle for calculating the durability limits of tire components. It is assumed that tire compounds, even at the manufacturing stage, contain microscopic flaws that are likely to propagate under the tire’s duty cycle. The critical plane analysis technique is adopted for the fatigue life prediction in this work. The critical plane analysis technique considers that crack precursors develop along specific planes of varying orientations. It then computes the number of cycles required to develop a crack precursor on each possible plane until failure. The plane with the shortest life is identified as the critical plane, and thus, represents the fatigue life of the tire part. The parallel rheological framework material model is used to characterize the nonlinear response of the rubber materials for accurate heat generation rates computation. The thermal-stress finite element analysis is carried out in ABAQUS and the resulting thermal strains imported into FE-SAFE/RUBBER for the fatigue life prediction. This paper attempts to locate a critical region in a 56/80R63 mining truck tire with the worst fatigue life.