The Effect of Ply Lay-Up Sequence on the Fracture Toughness of Boron Aluminum

Abstract

The fracture toughness of 0/90° cross ply boron reinforced aluminum composites has been investigated using prenotched compact tension and center notched tensile specimens. The effects on fracture toughness of specimen geometry, the relative numbers of 0° and 90° plys, and the lay-up sequence, have been measured. Ply lay-up sequence has been shown to affect fracture morphology and in turn alter the value of toughness. This has been related to the degree of matrix deformation which can take place to blunt the advancing crack. The relative numbers of 0° and 90° plys has been shown to be the major controlling factor and simple calculations based on a rule of mixtures approach provide reasonable agreement with the experimental data.

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.…”

Measurement of the in situ ply fracture toughness associated with mode I fibre tensile failure in FRP. Part II: Size and lay-up effects

“…Prewo [5] investigated the effect of ply lay-up sequence on the measured toughness for various cross-ply Boron-Aluminium CT specimens. By measuring K Ic for fracture initiation, it was found that the blocking together of plies, i.e.…”