PHIMECA carried out the study of a storage system in order to analyse the multiaxial fatigue lifespan of the structure under different load scenarios (parts loading and forklift movement).
Example of a storage system
The Crossland multiaxial fatigue criterion was used to postprocess the calculation results. This criterion considers the multiaxial behaviour of the most requested areas. It assumes that the initiation of a crack is strongly affected by two values:
- The maximal hydrostatic pressure on a cycle
- The magnitude of the shear stress in the octahedral plan
The Crossland threshold associated with the material is then determined. The equation that represents the Crossland threshold is as follows:
For every point of the model, the 2 characteristic values (pressure and magnitude of the shear stress) are located on the Crossland’s diagram and so, a number of cycles before the crack initiation can be estimated for the most critical point.
Crossland’s Diagram
Tools: Ansys, Python