Investigations on adhesively bonded curved CFRP panels with closed debonds subjected to compressive load

This present work aims to investigate the effect of debonds on the structural performance of adhesively bonded curved carbon fiber reinforced plastic (CFRP) panels under compressive loading environment. Representative curved panels are fabricated with a quasi-isotropic lay-up. Two types of specimens are prepared for the studies, one without debonds and the other with debonds of specified size, artificially introduced within the lap region. Pulsed thermography non-destructive technique is employed for the detection of debonds on the specimens. A set of experiments are conducted with displacement, strain and acoustic emission sensors to ascertain the performance of adhesively bonded joints under compression loading. Computational analyses are carried out using commercial finite element code MSC/NASTRAN to reproduce the experimental behavior and to aid in understanding the effect of closed debonds on the bonded joints. The computational model predictions are in good agreement with experimental observations. The effects of location of debond and panel curvatures are studied computationally incorporating debonds of different sizes. It is observed that debond location along the specimen length has significant effect and the buckling load reduces when the panel curvature increases for the same debond size.