What is the stress term called that is induced by the tendency for the upper fibers to slide over the lower fibers as a beam bends?

The stress term induced by the upward movement of the upper fibers sliding over the lower fibers in a bending beam is known as horizontal shear parallel to the grain. This occurs in materials such as wood, where the fibrous structure allows for different layers to experience varying levels of stress during bending.

When a beam bends, the upper fibers are subjected to compression, while the lower fibers experience tension. However, due to the nature of the material’s grain structure, as the beam bends, there is a tendency for these fibers to slide past one another, leading to shear stress. This shear stress contributes to the overall structural behavior of the beam, particularly in how it might fail or deform under load.

Understanding this concept is crucial for engineers and contractors when designing wooden structures, as it helps in determining the appropriate materials and methods to ensure the structural integrity of beams and other components subjected to bending forces. Other terms in the question, while related to material behavior and response to forces, do not specifically describe this type of stress.