Which of the following is NOT a fundamental kind of stress that building materials are subjected to?

Friction is not considered a fundamental kind of stress that building materials experience. The primary stresses in materials are tension, compression, and shear.

Tension refers to the pulling or stretching force that attempts to lengthen the material. Compression involves forces that push or compress a material, reducing its length and increasing its density. Shear stress occurs when forces are applied parallel to a material's surface, causing layers of the material to slide past each other.

Friction, although it can affect movement and force distribution within materials, is not classified as a fundamental stress type itself. Instead, friction is a force that can arise from the interaction of materials under tension, compression, or shear but does not represent a direct type of stress acting on the materials.