Shear strength of the bulk resin is quoted by resin manufacturers or calculate form G=E/2(1+v). Doesn't have a lot of practical use though. If after shear strength of a fibreglass laminated joint a figure of 7 MPa (100psi) glue bond area layup strength is used in many codes etc for CSM, with a safety factor of 4 (min) on top of this. Refer BS4994 or RTP-1 or FRP pipe codes. BS4994 has table for different FRP ply materials, or refer texts.
G = shear stiffness; it has nothing to do with shear strength. Strength in general cannot be calculated. See material vendor datasheets for typical properties. Typical shear strength of epoxy materials is in the 8-15 ksi range at room temp; vinylester probably has similar values.
It depends on many factors, but I think a cloth reinforced panel with Vf = 50% and low voids should be in the 7-8 ksi range. I seen up to 12 ksi with epoxy/glass uni-broadgoods and generally vinylester has similar properties to an epoxy at room temp.
