Steel wheels are often essential parts for heavy construction equipment, such as constructed by Huisman. These steel wheels must endure heavy loads. In order to prevent downtime, costs and to guarantee safety, it is important that the steel wheels do not fail. One important failure mode is failure resulting from subsurface initiated cracks. This research is focused calculating the allowable load for steel wheels with initial cracks as a function of the number of cycles.

The allowable load will be calculated using four different methods. Fracture mechanics will be applied, which uses an initial crack size and a load case to calculate the number of cycles until failure. The three other methods that will be discussed are described by fabrication standard, which are used during design of steel wheels. An analytical model will be used which applies all four methods to calculate the allowable load as a function of lifetime.

The results will be analyzed in order to understand the differences between the methods. Also, parametric research will be done in order to understand the effects of the fracture mechanics input parameters. Furthermore, experimental data will be used in order to estimate which method is most realistic. It can be concluded that fracture mechanics can be used to calculate the allowable load for steel wheels if the correct values for the input parameters are known. The acquired data is very limited, however, which indicates that more data must be gathered in order to specify the input parameters for specific situations and materials.