Analysis of fatigue behaviour of a vehicle axle steering arm based on Local stresses and strains

Using the example of a randomly loaded forged bus axle steering arm theoretical procedures concerning the description of technological effects such as the surface roughness and the residual stress state within the framework of the Local Strain Approach are discussed, Calculation analyses are performed using the damage parameter of Smith, Watson and Topper [1 ] and the one developed by Vormwald [2]. Corresponding test results are used to check the accuracy of the calculations. The calculated life values indicate the significant influence resulting from the interaction between surface roughness and residual stress state on fatigue behaviour. In addition, the good agreement between calculated and experimentally determined results emphasises the valuable assistance given by the Local Strain Approach for fatigue-resistant design of such components.