EVALUATION OF MICROSCOPIC DEFORMATION IN CFRP LAMINATES WITH DELAMINATION BY MICRO-GRID METHODS

Micro-grid methods were applied to measure displacements in 90 degrees ply in CFRP cross-ply laminates with only transverse cracks or with b oth transverse cracks and delaminations. The COD (crack opening displa cement) of the transverse cracks were also measured. Micro-grids were printed on the specimen edge surfaces by using the photo-lithography t echnique. The displacement fields of the specimen edge surface obtaine d from the experiment were compared with McCartney's [1] and Lee et al .'s [2] analyses which predicted the displacement field of a cross-ply laminate with only transverse cracks. Furthermore these analyses were modified to consider the existence of delamination.