When a load is applied to a beam it will deform by bending, which generates internal stresses within the beam. These internal stresses can be represented by a shear force and a bending moment acting on any cross-section of the beam. The shear force is the resultant of vertical shear stresses, which act parallel to the cross-section, and the bending moment is the resultant of normal stresses, called bending stresses, which act perpendicular to the cross-section.
The video below covers these bending and shear stresses that develop in beams in more detail.
Which part of a structural I-beam carries most of the shear loading?
The web
The flanges
The web and the flanges carry shear loading evenly
The shear stress distribution in a structural I beam is shown in the image below. The shear stresses reach a maximum value at the neutral axis, which is located at the centre of the web, and are zero at the extreme fibres in the flanges. The vast majority of the shear load is carried by the web.
