Yield Point

Yield point, also called yield strength, is a term used in materials science and engineering to describe the point at which a material begins to deform plastically under stress, without any additional increase in the applied stress.  In other words, the yield point is the stress level at which a material undergoes a transition from elastic deformation, where it returns to its original shape after the stress is removed, to plastic deformation, where it retains a permanent deformation after the stress is removed.

The yield point is an important characteristic of a material, as it determines the maximum stress that the material can sustain without permanent deformation.  It is often used as a design parameter in engineering applications, such as the design of structures or machine components, where the material's yield point must be higher than the expected stress level to ensure that the component does not deform or fail under load.  The yield point is typically determined through mechanical testing of a material, such as a tensile test, where a sample of the material is subjected to increasing levels of stress until it reaches the point of yielding.  The yield point is then calculated based on the stress level at which the material begins to deform plastically.

Different materials have different yield points, and the yield point can also be affected by factors such as temperature, strain rate, and material defects.  It is important to consider the yield point when selecting materials for engineering applications, as a material with a higher yield point can generally withstand higher stress levels without deforming or failing.