Selection of an in-plane shear test method based on the shear sensitivity of laminate tensile modulus

The sensitivity of the tensile modulus for a number of Hercules AS4/3501-6 laminates to changes in the values of in-plane shear modulus was used to select the fibre orientations for four highly shear-sensitive laminates of the form ±θ₁,±θ₂]_3s. The in-plane shear moduli for the Hercules AS4/3501-6 composite material were then determined for 90° Iosipescu, 10° off-axis tensile and ±45° tensile specimens. These values were used with classical laminate plate theory to predict laminate tensile moduli. The best agreement between these predicted values and those which were experimentally measured was obtained when the ± 45° tensile test method was used to determine the in-plane shear modulus.