Hydrothermal fatigue on interface of glass-epoxy laminates

Many theories point out the complexity of the phenomena that manifest at the fiber-matrix interface or interphase. The interphase in glass fiber composites is reasonably reported to be a film, which is also a polymer. Glass fibers of 55, 60, and 65 wt% are used to fabricate epoxy matrix polymer composites. The test specimens are treated first at 50 degrees C in a water bath for 30 min and then immediately immersed in another water bath at 100 degrees C for the same time. The hydrothermal treatment was carried out for different cycles. The three-point bend short beam shear test was performed on the conditioned samples for two different crosshead speeds (2 and 50 mm/min). The aim of the experiment is to assess the weakening effect of thermal shock and fatigue during hydrothermal aging on the interlaminar adhesion of varied weight fraction constituents in the composite. The variations in loading speed and the moisture content were taken into consideration for the assessment of interface-matrix damage by the cyclic conditioning.