Drive axle housing failure analysis of a mining dump truck based on the load spectrum

One of the key components in a mining dump truck is the drive axle housing. Failure of this component during normal use is unacceptable. Recently, early fatigue fracture became a problem during the normal working process of these machines. However, it is difficult to calculate exactly the fatigue failure life of the drive axle housing based on bench testing or pure computer simulation due to the differences between practical road conditions (such as slope and roughness) and simplified boundary conditions. To increase the reliability of analysis results a new analysis method based on dynamic strain measurement from practical mine road surface conditions combined with finite element analysis is proposed in this paper. The dynamic strain and stress on the drive axle housing is obtained by strain measurements while the truck travels over normal mine road surface conditions. The dynamic stress was analyzed using the rain-flow counting method, which can determine the amplitudes and mean values of counted cycles. The influence of the stress mean value was taken into consideration with the Morrow’s model. According to the assumption of a linear Palmgren–Miner hypothesis of damage accumulation and using typical fatigue characteristics of the material, the fatigue failure life was calculated. Analysis of the measurements showed that the dynamic stress experienced by the axle housing was far greater than expected. In order to find the factors affecting the dynamic stress of the drive axle housing, the slope of the road surface, any uneven loading and eccentricities were analyzed using the finite element method. This paper shows that the new analysis methods described are valuable tools for analyzing the reasons behind the failure of these truck axle housings.