The effect of surface treatments on the interlaminar shear failure of GLARE laminate included AA6061-T6 layers by comparing failure characteristics

The effect of surface treatments on hot-pressed GLARE 3/2 laminates included AA6061-T6 is evaluated in this paper. Sandpapering, degreasing and both degreasing and sandpapering are applied on AA6061-T6 sheets in order to contribute the improvement of the interlaminar shear strength (ILSS). The three-point bending tests are carried out by using two different span length-to-specimen thickness ratios (S/h) to examine also the effect of shear and bending on deformation and failure characteristics. Strength values and failure modes are obtained for both S/h ratios and all surface treatment types. Load-displacement and stress-displacement curves are evaluated. The results show that the maximum shear strength values for surface-treated laminates are increased by between 29% and 37% against untreated one. It is observed that the strength values and failure modes of all surface-treated GLARE laminates are influenced by an increase in the S/h ratio from 4.0 to 10.0 because of the increase in bending effect against shear.