PROCESS DEVELOPMENT FOR FABRICATION OF HONEYCOMB SANDWICH STRUCTURE USING ELECTRON BEAM CURE MATERIALS

摘要

Five processing scenarios were evaluated for assembly of honeycomb sandwich structure using electron beam cure adhesives and prepreg materials. Three secondary bond scenarios and two co-cure scenarios were evaluated for fillet formation and tensile strength. The specimens were through-transmission ultrasonically inspected, optically micrographed, and flat-wise tensile tested to evaluate the effect of processing on bond formation and strength. A co-cure bonding method without adhesive demonstrated the greatest tensile bond strength, as well as lowest variation in fillet size and ultrasonic transmission. A co-cure method that used a calculated areal weight film adhesive resulted in a lower tensile strength, and generated fillets with greater variation in size, as well as resulted in greater variance in ultrasonic intensity compared to the co-cure method without adhesive. Roller coating of a paste adhesive provided a stronger tensile strength when secondarily bonded than the bond generated by a controlled thickness or calculated areal weight film adhesive. However, the calculated areal weight film bond resulted in the greatest consistency for fillet size formation, as well as consistency in ultrasonic intensity.