Fracture of thick laminated composites

Thickness-dependence of the translaminar fracture toughness: Experimental study using thin-ply composites

“…The ply-block thickness effect on the onset of micro-cracking and delamination has been extensively analysed [1][2][3][4][5][6]. Kim and Soni [7] investigated several quasi-isotropic layups, with different layups sequences while keeping the same ratio of each constituent ply; the authors showed that the delamination 5 threshold decreased with increasing ply-block thickness.…”

Comparison of open hole tension characteristics of high strength glass and carbon fibre-reinforced composite materials

“…Generally, carbon fibre-reinforced plastics (CFRP) have been the composite material of choice for use in primary structures due to their high specific strength and modulus. As such, a considerable literature exists on the damage characteristics of notched CFRP laminates [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17].…”

“…It has been widely reported that notch tip damage prior to ultimate failure has a direct effect on CFRP laminate notched strength [5,6,8,10]. Intralaminar damage at the notch tip provides stress relief as the notch geometry changes and the stress concentration is reduced, hence increasing the notched strength.…”

“…Harris and Morris [8] examined the effects of laminate thickness and found that in thick laminates, pre-failure damage near the notch only occurred in the outer plies; thus the greater the laminate thickness, the less effect damage had on the stress distribution prior to failure.…”

Modeling of Mechanical Behavior of Notched Composite Laminates

“…The reason is that in the case of thinner laminates the longitudinal cracks (splits) play a greater role on relieving and redistributing the local stresses at the notch tip and hence increasing the value of the notched strength. In the case of thicker laminates it was found that the axial splits were limited to the outer or boundary layers and hence less stress redistribution would be made [16]. It was also noted that the length of axial splits prior to failure in thick laminates was less than that for thin laminates.…”