Effective Shear Modulus GAeff

In this equation effective shear modulus GA_eff is calculated using the Shear Analogy Method, given in O86 8.4.3.2 and. CLT Handbook 3.3.1, Equation 25.

GA_eff = a² / b ∑ α _i t _i / G_i

where the summation i is over all the layers and

• a is the distance between the midpoints of the outermost layers,
• b is the one-foot arbitrary design width.
• α _i = ½ for the outermost layers and 1 for the inner layers
• t _i is the thickness of the layer
• for layers parallel to loading, G_i = G = E_i/16 (PRG 320 Table A1, Note d)

for layers transverse to loading, G_i = G /10 (PRG 320 Table A1, Note d)

Double Outermost Layers

Double outermost layers are treated as a single layer in this calculation.