Moisture absorption and interfacial failure in aramid/epoxy composites

Yang

et al. 2020

Composite Structures

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Section: A B C A B Cmentioning

confidence: 99%

Modelling and experimental validation on drilling delamination of aramid fiber reinforced plastic composites

Yang

et al. 2020

Composite Structures

WIT Transactions on the Built Environment, Vol 85

“…Galiotis et al [3], Patrikis et al [4], Cervenka et al [5]). In this work, a single-fiber pull-out model composite for an aramid/epoxy system was specially designed and Raman spectroscopy was used to clarify the difference of stress distribution along the fiber before and after the interfacial debonding.…”

Section: Introductionmentioning

confidence: 99%

Measurement of the fiber stress distribution during pull-out test by means of micro-Raman spectroscopy and FEM analysis

Tanaka¹,

Minoshima²,

Yamada³

2006

A single-fiber pull-out model composite for an aramid/epoxy system was specially designed to measure the stress distribution of the aramid fiber embedded in the matrix using micro-Raman spectroscopy. The stress transfer length of the fiber obtained was about 400-500µm, which was equal to the result of FEM analysis. Just after the initiation and propagation of the fiber/matrix interfacial debonding, the fiber was broken, and the fiber in the matrix had the axial tensile residual stress. The tensile residual fiber axial stress showed the maximum at around the tip of the interfacial debonding. The stress was reduced and became almost equal to zero after being immersed in deionized water at 80 °C for 44h. This behavior agreed with the result of FEM analysis, in which the friction coefficient was introduced in the fiber/matrix interface.

“…On the other hand, in long-term applications, moisture and temperature have been shown to have deleterious effects on performance of advanced carbon/epoxy composites (8) . Some studies have also shown variation in residual stresses under hygrothermal exposure of aramid fiber/epoxy (4) and aramid fiber/polyester (5) single-fiber composites. These studies were under constant environments and experiments performed under variable environmental conditions were not found.…”

Section: Introductionmentioning

confidence: 99%

Dependence of Fiber Stresses on Cyclic Changes of Temperature and Water Absorption in Carbon/Epoxy Single-Fiber Model Composites

Miyake

Futamura

Fujiyoshi

et al. 2010

JMMP

In this study, we examine the variation in residual stresses in polymer matrix composites with cyclic changes in hygrothermal environments by measuring the axial stresses in the fiber of single-carbon fiber/epoxy resin model composites using Raman microspectroscopy. To change the temperature and water absorption in the specimens separately and simultaneously, the specimens were (1) heated and cooled at atmospheric environment, (2) immersed in water and dried at room temperature, and (3) immersed in hot water (80°C) and cooled to room temperature in water and then dried. All specimens were thus restored to their initial states and then evaluated. In the cases of (1) and (2), the fiber stresses reverted to almost the same as their initial states, but in the case of (3) the axial stress after hygrothermal cyclic change was more compressive compared to the initial state. The differences among the results of the three cases are discussed based on the fiber stresses at elevated temperature, which were evaluated by Raman microspectroscopic measurement performed at temperatures ranging from room temperature to those above the glass-transition temperature of the epoxy matrix resin.