5 research outputs found
MIXED MODE FRACTURE TOUGHNESS OF CRACKED SPECIMENS MADE OF NANOMODIFIED EPOXY RESIN
In the present work the effects of nanoclay addition on fracture behaviour of an epoxy resin
under mixed mode (I plus II) loadings are studied by analysing the results from Single Edge
Notch Bending (SENB) specimens. The results allow to conclude that, for weight contents
lower than 5 wt.%, nanomodification significantly enhances the fracture toughness of the
epoxy resin upon the entire range of mixed mode loadings, the improvements being dependent
on the mode mixity ratio.
Experimental results are later compared to the theoretical predictions based on different, well
acknowledged, mixed mode fracture criteria. The results from specimens made of pure epoxy
are well predicted, almost independently of the approach used for the synthesis. Conversely,
as far as the results from specimens made of nanomodified polymer are concerned, the
agreement with theoretical predictions is much poorer. This can be thought of as linked to the
emergence, of different damaging mechanisms due to nanomodification depending on the
mode mixity