Paper number 252

DELAMINATION BEHAVIOUR OF Z - PINNED LAMINATES

Denis D.R. Cartié and Ivana K. Partridge

Advanced Materials Department, School of Industrial and Manufacturing Science
Cranfield University, Cranfield, Bedford, MK43 0AL, UK

Summary

The paper presents the new technique of Z - fibre pinning as an approach to improving the through-thickness properties of continuous carbon fibre reinforced thermoset resin laminates. It describes the preparation of double cantilever beam delamination test specimens made from IMS/924 pre-pregs, pinned with carbon fibre/BMI pins. Delamination crack propagation resistance in Mode I loading conditions is found to increase from 200 J/m2 in the control sample to nearly 5kJ/m2 in specimens pinned with a high areal density of the Z-pins. Under Mode II loading conditions, the Z-pinned ENF specimens are found not to exhibit the expected catastrophic failure mode; the crack propagation delamination resistance reaches 7kJ/m2 in the strongest specimens. The delamination behaviour of the Z-pinned specimens subjected to varying mixtures of Mode I and Mode II loading evolves in the expected manner. The fracture results are discussed in relation to the mesostructure of the samples.

Keywords

Z direction reinforcement, Z-pins, delamination, Mode I, Mode II, MMB, mesostructure