High-cycle fatigue investigations of notched Glare under different stress ratio's in various environments

Notched Glare 4A-3/2 laminates, comprising thin 2014-T6 aerospace aluminum alloy sheets alternately bonded with unidirectional E-glass fiber-based composite prepregs, are tested under tensile-tensile fatigue load with different stress ratio’s ranging from 0.1 to 0.5 in ambient, aqueous, and corrosive environments in high-cycle conditions. Fatigue characteristics of the laminates are found to be influenced by the operating environment and the magnitude of stress ratio. Notched plain 2014-T6 aerospace aluminum alloy specimens are also subjected to identical cyclic stress levels as in aluminum alloy layers of the laminates for comparative analysis of their fatigue behavior with those of the laminates. Retarded crack growth rates in the laminates leading to their enhanced fatigue lives and higher cyclic fracture toughness values vis-à-vis plain specimens substantiate fiber bridging effect in the laminates.