THE EFFECTS OF STACKING SEQUENCE ON COMPOSITE COMPRESSIVE PERFORMANCE AND HOW TO IMPROVE IT

Uni-directional fibre-reinforced composites demonstrate a lack of mechanical strength in compression Experimental tests according to ASTM D5467 were used to obtain the compressive performance of IM7/8552 unidirectional carbon fibre with various stacking sequences. The response shows a reduction in stiffness with increasing strain. An analysis of the non-linear stiffness of the different configurations shows that the non-linear stiffness variation is similar for uni-directional and multi-directional laminates. Experimental results show that the initial stiffnesses of multi-directional laminates are similar to those calculated using classical laminate plate theory. The uni-directional laminate shows a longitudinal stiffness of 15% less than expected. Uni-directional, cross-ply, and quasi-isotropic laminates show a non-linear longitudinal stiffness reduction of 7% at an applied compressive strain of 1%.