Damage Behavior of Carbon/Epoxy Laminated Composites Composed of Super-Thin Plies

According to past research, using thinner layers usually results in a stronger composite. Along with the size effect, thinner layers also lead to a larger interfacial area, which enhances load transfer. In this work, a super-thin carbon/epoxy prepreg was utilized for making laminated composites. The prepreg thickness was 23 microns, which is about five-times thinner than conventional layers. Specimens of cross-ply laminates were prepared and cured by compression molding. Two types of specimen panels were made, composed of 50 and 60 layers of the super-thin ply. For comparison purposes, specimens composed of 8-layer standard plies were made. All these specimens have the same carbon fiber and epoxy resin, and their fiber contents are very close. Three-point bending and compressive tests were conducted. Scanning electron microscopy (SEM) was used to observe the induced damage. The results indicate that the properties were notably improved by using the super-thin plies. The fracture behavior and induced damage modes were very different. Some unique damage patterns were observed, which were unseen in composites composed of standard plies.