The effect of fatigue crack length on the residual strength of ARALL3 panels with fingertip doublers

Fatigue and residual strength tests were done on doubler specimens consisting of an ARALL3 (3/2) laminate with a bonded-on fingertip doubler. The primary objective was to determine the effect of fatigue crack length on the residual strenght and delamination onset stress for this type of specimen. The specimens were precracked to variable crack...

Fatigue damage in composites under different loading conditions

The damage development In notched (± 45, 0„, 90, 0-) carbon-epoxy coupon specimens tested under different loading conditions was determined. Constant amplitude tests at R = -1 and R = 0.1 as well as flight simulation tests were performed to establish those stress values for which no damage growth occurs.