SELECTION OF AN INPLANE SHEAR TEST METHOD BASED ON THE SHEAR SENSITIVITY OF LAMINATE TENSILE MODULUS

The sensitivity of the tensile modulus for a number of Hercules AS4/35 01-6 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 [+/- theta(1), +/- theta(2)](3S). The in-plane s hear moduli for the Hercules AS4/3501-6 composite material were then d etermined for 90 degrees Iosipescu, 10 degrees off-axis tensile and +/ -45 degrees tensile specimens. These values were used with classical l aminate plate theory to predict laminate tensile moduli. The best agre ement between these predicted values and those which were experimental ly measured was obtained when the +/-45 degrees tensile test method wa s used to determine the in-plane shear modulus.