FRACTURE MECHANICS

KOT Engineering works with customers in the diagnosis and solution of maintenance problems. The fracture mechanics is an important tool to predict crack growth, mainly in welded structures.

This method can provide a good estimation of the component’s fatigue life, when the failure occurs in a number of cycles below the determined by the classic fatigue theory.

The fracture mechanics method assumes that small discontinuities are inherent to manufacturing process such as welding and machining. The initial crack length is normally assumed as equal to 0,5 mm.

To the crack propagation calculation, the BS-7910 standard is adopted through, also a finite element software is used to determine the stress field at the tip of the crack at each propagation step. Finally, the number of cycles as function of the crack length is determined.