The effects of void contents on the long-term hygrothermal behaviors of glass/epoxy and GLARE laminates

In this paper the effect of voids formed in both the glass/epoxy and GLARE laminates on their long-term hygrothermal behaviors are evaluated. By adopting different autoclave pressures during a cure cycle, the specimens with different void contents ranging from 0.5% to 2.0% were obtained for both materials. Two types of hygro and thermal aging tests were then carried out according to water absorption in distilled water and thermal cyclic fatigue up to 1500 cycles, respectively. The resulting behaviors of degradation for both materials due to two types of aging tests were evaluated by the test for interlaminar shear strength which is highly affected by those types of aging. Experimental results indicate that the autoclave pressure enhances a certain extent of the GLARE’s interfacial bonding with the low void contents. It therefore leads to an increase in the resistance to the hygro and thermal agings.