On the Energy Release Rate of Fatigued Composites Subjected to Compressive Overloads

Abstract

The behavior of delaminated graphite/epoxy composites under variable amplitude compressive loading (spectrum loading) is studied. The delamination growth is monitored in real time during fatigue tests. Different variable amplitude compressive load spectra are applied. Calculations of the energy release rate, G, as a function of the delamination length, delamination position, and applied strain during the spectrum loading are performed. Numerical simulations are based on a mixed mode fatigue growth model that is not subjected to the thin film model restrictions. The higher energy release values during the overloads were associated to the formation of intralayer and interlayer cracks on the composite specimens. [S0094-4289(00)03004-8]

Delamination growth behavior in carbon fiber reinforced plastic angle ply laminates under compressive fatigue loads

“…if the energy release rate is less than the critical value). 19 Although several decades have elapsed since the recognition of the importance of delamination failure, it still remains a determining factor limiting the use of structural elements made of laminated composites. [20][21][22][23] New developments, predominantly in the aircraft field, compel us to complete the knowledge of delamination growth behavior under compressive fatigue loads, which is essential to establish design allowable guidelines for structures.…”

“…if the energy release rate is less than the critical value). 19 Although several decades have elapsed since the recognition of the importance of delamination failure, it still remains a determining factor limiting the use of structural elements made of laminated composites. 20–23…”