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Wood Shear Stress Formulas and Calculator

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Wood Shear Stress Design Formulas and Calculator

The actual shear stress parallel to grain induced in a sawn lumber, structural glued laminated timber, structural composite lumber, or timber pole or pile bending member shall be calculated as follows:

Preview: Wood Shear Stress Design Calculator

Eq. 1
fv = V · Q / ( I · b )

For a rectangular bending member of breadth, b, and depth, d, this becomes:

Eq. 2
fv = 3 · V / ( 2 · b · d )


fv = actual shear stress parallel to grain, psi
= Shear force, lbs
Q =
statical moment of area about the neutral axis, in3
I = area moment of inertia in4
b = breadth (thickness) of rectangular bending member, in.
d = depth (width) of bending member, in.



National Design Specification for Wood Construction, 2017