INNOVATIVE APPROACHES COMPATIBLE WITH WET LAMINATING PROCESSES SUCH AS FILAMENT WINDING ARE SOUGHT WHICH WILL ELIMINATE OR REDUCE FORMATION OF VOIDS DUE TO ENTRAPPED AIR.

INNOVATIVE APPROACHES COMPATIBLE WITH WET LAMINATING PROCESSES SUCH AS FILAMENT WINDING ARE SOUGHT WHICH WILL ELIMINATE OR REDUCE FORMATION OF VOIDS DUE TO ENTRAPPED AIR. THE PROBLEM HAS BEEN THAT IN ADDITION TO AIR BUBBLES CONTAINED IN THE EPOXY ITSELF, AIR BUBBLES ARE ALSO TRAPPED BETWEEN RESIN AND THE FIBER DURING THE WETTING PROCESS. UPON CURING, VOIDS ARE CREATED WHICH REDUCE THE PERFORMANCE OF THE COMPOSITE. ALTHOUGH NON-DESTRUCTIVE EVALUATION TECHNIQUES ARE AVAILABLE TO SPOT THE VOIDS AND HELP TO DETERMINE THEIR SIGNIFICANCE, A PRODUCT FREE OF VOIDS AND POROSITIES IS DESIRED. THE APPLICATION OF ULTRASONIC ENERGY TO THIXOTROPIC AND VISCOUS MATERIALS HAS CONSISTENTLY DEMONSTRATED FLOW PROMOTION EFFECTS. ADDITIONALLY, ULTRASONIC ACTIVATION CAN IMPORVE OR CAUSE FLOW AT SIGNIFICANT LOWER TEMPERATURES THAT WOULD BE REQUIRED WITHOUT ULTRASONICS. AS DEMONSTRATED BY OUR EARLIER WORK, APPLICATION OF ULTRASONICS DURING RESIN PREPARATION, PREPREG PREPARATION AND COMPOSITE LAY-UP AND CURE CAN PROVIDE UNIFORM RESIN FLOW AND WETTING. THE OBJECTIVE OF THIS PHASE I EFFORT IS TO DEMONSTRATE THE TECHNICAL FEASIBILITY OF UTILIZING ULTRASONIC REACTION ENHANCEMENT TO CAUSE 100% "WET-OUT" OF RESIN MATRIX COMPOSITES. THE TOTAL IMPREGNATION OF THE FIBERS WOULD ELIMINATE TRAPPED AIR THUS ELIMINATING VOIDS AND POROSITIES. THIS TECHNICAL FEASIBILITY DEMONSTRATION WILL PROVIDE THE ENGINEERING DATA NECESSARY FOR FURTHER PHASE II AND III DEVELOPMENT OF PRODUCTION ARRAYS.