OPTICAL FIBER JET PLACEMENT FOR TRIAXIAL REINFORCEMENT/DELAMINATION MONITORING OF COMPOSITES

COMPOSITE LAMINATES MAY IMPROVE AEROSPACE STRUCTURES, IF THE COMPOSITES DON'T DELAMINATE. DELAMINATIONS RESULT IN UNPREDICATBLE STRENGTH AND STIFFNESS REDUCTIONS AND ARE DIFFICULT TO DETECT. THIS PROJECT PLACES TRIAXIAL ARRAYS OF OPTICAL GLASS FIBER IN LAMINATES. WHEN DELAMINATION OCCURS, THE OPTICAL FIBERS BREAK AND THE DELAMINATION CAN BE DETECTED BY SIMPLE OPTICAL INSPECTION. THE FIBERS ALSO REDUCE THE INCIDENCE OF DELAMINATION. THE OPTICAL FIBERS ARE PLACED IN UNCURED LAMINATES BY HIGH SPEED IMPACT. DEVELOPMENT OF A SIMPLE TECHNIQUE FOR PLACING TRIAXIAL REINFORCEMENT AND FOR IN-SERVICE INSPECTION OF COMPOSITE LAMINATES WILL HAVE A MAJOR IMPACT ON THE ACCEPTANCE OF COMPOSITES FOR USE IN CRITICAL AEROSPACE STRUCTURES.