Experimental investigation on the effect of creep on the damage evolution of CFRP structures during fatigue loading

This paper presents an experimental investigation on the effect of creep on the damage evolution of Carbon Fiber Reinforced Polymer structures during fatigue loading. A new experimental campaign is proposed where unidirectional CFRP specimens are tested under the combination of fatigue and constant compressive load. The tests represent the loading that the lower part of an air-wing faces during the flight and parking process. Acoustic Emission technique is employed in order to monitor the damage progression and accumulation. The results of the acoustic emission are compared with reference tests where only fatigue loading is used and it is found that the acoustic emission patterns in terms of number and distribution of events over the duration of tests and energy accumulation is different for these two types of tests. The results indicate that the damage process on CFRP structures is different when creep is present.Structural Integrity & Composite