Interface damage study of hydrothermally aged glass-fibre-reinforced polyester composites

Two types of glass-fibre-reinforced polyester composites have been immersed in water at different temperatures (from 30 to 100 degrees C) and subjecte d to gravimetric analysis, mechanical tests, and microscopic observations. Three types of damage have been identified: osmotic cracking in the matrix. at the intel phase and interfacial debonding. It is suggested that matrix osmotic cracking is responsible for weight loss. The decrease of interlamin ar shear strength (ILSS) is explained mainly by interfacial debonding, indu ced by differential swelling, and by osmotic cracking at the interphase but the matrix also contributes to the decrease. In summary, composite lifetim e is greatly dependent on the ability of the matrix to microcrack under the service conditions. (C) 1999 Elsevier Science Ltd. All rights reserved.