Yieldpunt

Yieldpunt is the Dutch term used to refer to the yield point of a material in the context of mechanical engineering and materials science. It denotes the point on a stress-strain curve where the material transitions from elastic deformation, which is reversible, to plastic deformation, which is permanent.

In many metals, particularly certain steels, the curve displays an upper yield point followed by a lower yield point. At the upper yield point, the stress briefly rises to a maximum and then drops as dislocations break free and plastic flow begins. The lower yield point marks the continued onset of plastic deformation at a lower stress. Some materials do not show a distinct yield point and are described instead by a 0.2% offset yield strength.

Measurement is commonly done using a tensile test, with yield strength reported in megapascals (MPa). The 0.2% offset method defines the yield point as the stress at which permanent strain of 0.2% occurs, enabling consistent comparisons across materials.

Applications include structural design, where yield strength determines allowable stresses, and manufacturing processes such as forming and extrusion, where yielding behavior influences process parameters and product quality.

Although the term yieldpunt is chiefly used in Dutch-language contexts, the English equivalent is yield point. The concept is widely discussed in standards and textbooks on mechanical properties of materials.