Z-DIRECTION TAPE REINFORCEMENT FOR COMPOSITE LAMINATES

COMPOSITE LAMINATES MADE FROM CONVENTIONAL GRAPHITE-EPOXY ARE PRONE TO DELAMINATION DUE TO IMPACT OR EDGE EFFECTS. SOME MEANS OF IMPROVING COMPRESSIVE STRENGTH AFTER IMPACT IS DESIRED. STITCHING IS ONE OPTION, BUT CAUSES DAMAGE TO IN-PLANE PROPERTIES AND REQUIRES ACCESS TO BOTH SIDES OF THE LAYUP. THE PROPOSED TECHNIQUE UTILIZES SHORT BORON FIBERS ORIENTED IN THE Z (OR THICKNESS) DIRECTION TO REDUCE STRAIN ENERGY RELEASE RATE AND RETARD DELAMINATION. BORON FIBERS WILL BE INSERTED USING A SPECIALLY DEVELOPED REINFORCING TAPE. THE TECHNIQUE IS COMPLETELY COMPATIBLE WITH EXISTING PROCESSING METHODS AND CAN BE PERFORMED ON-TOOL. PROPOSED PHASE/I EFFORT CONSISTS OF TAPE DEVELOPMENT, PROCESSING AND STRUCTURAL TESTING OF SAMPLE Z-DIRECTION REINFORCED COMPOSITE LAMINATES.