Upper Yield Point - Uekou Fukuten

…In low- and medium-carbon steel, a clear yield point is observed, and as soon as plastic deformation begins, the stress drops slightly, and the plastic deformation progresses at that stress. The stress at which plastic deformation begins is called the upper yield point, and the stress at which it progresses is called the lower yield point. If plastic deformation occurs in a material, the deformation can become excessive, or the structure can become defective, such as not being able to return to its original shape even when the load is removed. …

*Some of the terminology that refers to "upper yield point" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…低中炭素鋼では明りょうな降伏が認められ，塑性変形の開始と同時にいったん応力は多少低下し，その応力で塑性変形が進展する。塑性変形の開始応力を上降伏点，進展する応力を下降伏点という。材料に塑性変形が生ずれば変形が過大になったり，荷重を取り除いても形が元に復元しなくなるなどの不つごうが構造に生ずる。…

※「上降伏点」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報