In mechanics, what does shearing refer to?

Shearing refers to the movement or failure of materials by sliding one part over another. This type of stress occurs when forces are applied perpendicular to the surface of a material, causing layers within the material to move in opposite directions. This action can lead to deformation or structural failure without necessarily breaking the material.

In practical applications, shearing is an essential concept in various mechanical processes, such as cutting metals, where forces cause layers of material to slide past each other rather than directly breaking them apart. Shearing is also relevant in understanding how materials behave under different loads and how they can be designed to withstand certain types of stress in construction and manufacturing.

The other options do not accurately describe the shearing process: breaking materials into smaller pieces involves different forces or methods, fracturing under pressure refers to a different type of failure typically associated with compressive stress, and stretching to the point of failure pertains to tensile stress rather than shearing.