TY - JOUR
T1 - Influence of specimen type and reinforcement on measured tension-tension fatigue life of unidirectional GFRP laminates
AU - Korkiakoski, Samuli
AU - Brøndsted, Povl
AU - Sarlin, Essi
AU - Saarela, Olli
PY - 2016/4/1
Y1 - 2016/4/1
N2 - It is well known that standardised tension-tension fatigue test specimens of unidirectional (UD) glass-fibre-reinforced plastics (GFRP) laminates tend to fail at end tabs. The true fatigue life is then underestimated. The first objective of this study was to find for UD GFRP laminates a test specimen that fails in the gauge section. The second objective was to compare fatigue performance of two laminates, one having a newly developed UD powder-bound fabric as a reinforcement and the other having a quasi-UD stitched non-crimp fabric as a reinforcement. In the first phase, a rectangular specimen in accordance with the ISO 527-5 standard and two slightly different dog-bone shaped specimens were evaluated by means of finite element modelling. Subsequent comparative fatigue tests were performed for the laminates with the three specimen types. The results showed that the test specimen type has a significant effect on the failure mode and measured fatigue life of the laminates. A significantly higher fatigue life was measured for the laminate with the powder-bound fabric reinforcement when compared to the laminate with the stitched reinforcement.
AB - It is well known that standardised tension-tension fatigue test specimens of unidirectional (UD) glass-fibre-reinforced plastics (GFRP) laminates tend to fail at end tabs. The true fatigue life is then underestimated. The first objective of this study was to find for UD GFRP laminates a test specimen that fails in the gauge section. The second objective was to compare fatigue performance of two laminates, one having a newly developed UD powder-bound fabric as a reinforcement and the other having a quasi-UD stitched non-crimp fabric as a reinforcement. In the first phase, a rectangular specimen in accordance with the ISO 527-5 standard and two slightly different dog-bone shaped specimens were evaluated by means of finite element modelling. Subsequent comparative fatigue tests were performed for the laminates with the three specimen types. The results showed that the test specimen type has a significant effect on the failure mode and measured fatigue life of the laminates. A significantly higher fatigue life was measured for the laminate with the powder-bound fabric reinforcement when compared to the laminate with the stitched reinforcement.
KW - Fatigue test methods
KW - Polymer matrix composites
KW - S-N curves
KW - Specimen design
KW - Unidirectional laminate
UR - http://www.scopus.com/inward/record.url?scp=84954185653&partnerID=8YFLogxK
U2 - 10.1016/j.ijfatigue.2015.12.008
DO - 10.1016/j.ijfatigue.2015.12.008
M3 - Article
AN - SCOPUS:84954185653
VL - 85
SP - 114
EP - 129
JO - INTERNATIONAL JOURNAL OF FATIGUE
JF - INTERNATIONAL JOURNAL OF FATIGUE
SN - 0142-1123
ER -