Fatigue Notch Factor
The stress concentration factor shows the ratio of fatigue strength of a smooth to a notched specimen. It helps in assessing stress distribution in weld areas.
Physicochemical mechanism of action
The stress concentration factor (K) is a measure of the change in fatigue strength due to notching. In smooth specimens, the stress distribution is homogeneous, while notched specimens exhibit local stress peaks.
Metallurgical relevance & risks in welding
A high stress concentration factor (K > 1) indicates increased stress distortion and potential cracks in the weld. This can lead to hot cracks or fractures if stress peaks are too high.
Workshop practice & instructions
To minimize the stress concentration factor and reduce the risk of cracks, pay attention to an optimal notch width. A notch width of 0.5 to 1 mm is generally suitable for many steel types. Always use a high-quality notching tool and adjust the notching speed to the material type.