In contrast to normal stress due to axial force, the magnitude of shear stress due to shear force is not same for every part of beam. The amount depends on distance from neutral axis. Highest shear stress occurs in area close to neutral axis, on contrary the lowest stress occurred in area located on surface of beam. The figure below shows the shear force on straight beam.
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| Figure 1: Shear Stress due to Shear Force |
Shear stress due to shear forces can be calculated using the following equation:
Where:
I = section of moment inertia
t = width of cross section
y = distance element to neutral axis
τ = shear stress