Notch Geometry
The notch shape defines the stress concentration in impact bend specimens and influences deformation behavior upon impact.
Physicochemical mechanism of action
The notch shape determines how strongly stresses are concentrated in the material. A V-notch (sharp indentation) leads to high stress concentration at the tip, while a U-notch (round indentation) distributes stresses over a larger area.
Metallurgical relevance & risks in welding
An incorrect notch shape can lead to increased stresses and thus to cracks or deformations. Excessive stress concentration can overstress the material and lead to fracture points, especially in fine materials.
Workshop practice & instructions
For a correct notch shape, it is crucial to make the indentation exactly according to the standard specifications. For impact bend specimens with a V-notch, the tip should be sharp and straight; for a U-notch, the radius of the curve should be uniform and sufficiently large (at least 2x the notch depth). The notch shape directly influences stress concentration and deformation behavior upon impact.