Beam shear
Beam shear is defined as the internal shear stress of a beam caused by the shear force applied to the beam.
Equation

where is
V = total shear force at the location in question;
t = thickness in the material perpendicular to the shear;
I = Moment of Inertia of the entire cross sectional area.
This formula is also known as the Jourawski formula.
Reference
(Stress shear)