Mode II fatigue delamination resistance of advanced fiber-reinforced polymer–matrix laminates: Towards the development of a standardized test procedure

Delamination resistance testing of fiber-reinforced polymer–matrix laminates under fatigue loads is important for materials development and structural design. Mode II in-plane shear fatigue test development using three-point bending end-notched flexure (3-ENF) and two-point bending end-loaded split (ELS) set-ups is performed in a round robin. Effects of specimen restraint observed earlier in ENF tests are confirmed and preliminary data indicate differences between the two set-ups, if simple beam theory or experimental compliance analyses are applied. Possible reasons for the observed disagreement are discussed.

► Cyclic fatigue loading in mode II yields lower delamination rates at comparable Gmax than mode I. ► The three-point end-notched flexure set-up for cyclic mode II fatigue requires a specimen fixation. ► There is a correlation between quasi-static and cyclic fatigue behavior for mode I and mode II.