Improved variable-amplitude fatigue behavior of a glass-fiber-reinforced hybrid-toughened epoxy composite
File(s)
Accepted version
Author(s)
Manjunatha, CM
Jagannathan, N
Padmalatha, K
Kinloch, AJ
Taylor, AC
Type
Journal Article
Abstract
A thermosetting epoxy polymer was hybrid-modified by the addition of 9 wt.% of rubber microparticles and 10 wt.% of silica nanoparticles. The GFRP composite laminates employing the unmodified epoxy matrix (GFRP-neat), and the hybrid epoxy matrix (GFRP-hybrid), were produced by a resin-infusion technique. The experimental fatigue lives of both GFRP composites under three different variable-amplitude load sequences, namely (a) a three-step increasing block (IB), (b) a three-step decreasing block (DB), and (c) a random block (RB) load sequence derived from a three-step load block, were determined. The fatigue life of the GFRP-hybrid composite was higher than that of the GFRP-neat composite under all the three load sequence blocks investigated, by about × 2.6 to × 4.0 times. The matrix crack density and the stiffness reduction rate were both lower in the GFRP-hybrid composite compared to the GFRP-neat composite material. The suppressed matrix cracking and reduced delamination growth rates in the hybrid-modified epoxy matrix enhanced the fatigue life of the corresponding GFRP-hybrid composite. Using the constant-amplitude fatigue data generated at various stress ratios, the fatigue lives under these variable-amplitude load sequence blocks were predicted using empirical models. The predicted fatigue lives, although conservative, were in reasonably good agreement with the experimental results.
Date Issued
2011-12-16
Date Acceptance
2011-11-10
Citation
Journal of Reinforced Plastics and Composites, 2011, 30 (21), pp.1783-1793
ISSN
1530-7964
Publisher
SAGE Publications
Start Page
1783
End Page
1793
Journal / Book Title
Journal of Reinforced Plastics and Composites
Volume
30
Issue
21
Copyright Statement
© Sage 2011. The final publication is available via Sage at https://dx.doi.org/10.1177/0731684411426202
Subjects
Science & Technology
Technology
Physical Sciences
Materials Science, Composites
Polymer Science
Materials Science
MATERIALS SCIENCE, COMPOSITES
POLYMER SCIENCE
variable amplitude
fatigue
hybrid composite
life prediction
DAMAGE ACCUMULATION
PLASTIC COMPOSITES
NANOCOMPOSITES
MATRIX
PREDICTION
TOUGHNESS
POLYMERS
STRENGTH
SEQUENCE
Publication Status
Published