Fatigue Life Prediction of Pultruded E-glass/Polyurethane Composites
Pizhong Qiao*
Mijia Yang
Advanced Materials and Structures Research Group, Department of Civil
Engineering, The University of Akron, Akron, OH 44325-3905, USA
* To whom correspondence should be addressed.
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Abstract |
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In this article, the tension-tension fatigue behavior of newly developed pultruded
E-glass/polyurethane composites is characterized, and an improved model for fatigue life
prediction including the effects of stress ratio, frequency, and mean stress as the
testing parameters is proposed. The proposed non-dimensional analysis is in good
agreement with the predictions of existing available fatigue data and present testing
data. The model is consistent with the Goodman line relationship and has a clear
physical meaning. The fatigue test data of E-glass/polyurethane composites are analyzed
using the proposed model, and they are compared with other common E-glass
fiber-reinforced plastic composites. It indicates that the E-glass/polyurethane
composites are more fatigue sensitive but comparable to other fiber-reinforced plastic
composites in their fatigue behaviors. The effects of stress ratio, frequency, and mean
stress on fatigue life of E-glass/polyurethane composites are studied and discussed. The
corresponding S-N curve and its bounds based on 95% confidence are provided for the
pultruded E-glass/polyurethane composites. The present fatigue model can be used as a
useful tool to characterize the effects of various parameters on the fatigue behavior of
fiber-reinforced plastic composites, and it provides the fatigue life prediction for
newly developed pultruded E-glass/polyurethane composites.
