Stiffness changes in laminates caused by intralaminar cracks and shear deformation
Academic Article
Overview
Additional Document Info
View All
Overview
abstract
An experimental study has been conducted to study stiffness changes in laminates containing inclined (off-axis) plies. The class of laminates studied is glass-epoxy (0, ± θ4, 01/2)s with θ = 25, 40, 55 and 70. It is found that for 0>40 multiple cracks occur in the θ-plies while for 6<40 no cracks are found. However, for all θ angles the laminate moduli change. A continuum damage mechanics approach is used to calculate stiffness changes due to cracks. In the absence of cracks the shear modulus reduction in the θ-plies, determined from independent tests on a (±45)s laminate, is found to provide good prediction of the observed stiffness changes.