What is the stress of the steel plate

Stress: When an object is deformed due to external factors (force, humidity, temperature field changes, etc.), an internal force that interacts between various parts of the object is generated to resist the effect of this external factor and try to make the object change from the deformed position to its pre-deformed position. The internal force per unit area at a certain point of the section under consideration is called stress. The perpendicular to the section is called normal stress, and the section tangent to the same section is called shear stress.

When the steel yields to a certain extent, due to the rearrangement of the internal grains, its resistance to deformation increases again. Although the deformation develops rapidly at this time, it can only increase with the increase of stress until the stress reaches the maximum value. After that, the ability of the steel to resist deformation is significantly reduced, and a large plastic deformation occurs at the weakest point, where the section of the specimen shrinks rapidly, necking phenomenon occurs, until fracture failure. The maximum stress value of the steel before tensile fracture is called the strength limit or tensile strength.