Powder Epoxy for One-Shot Cure, Out-of-Autoclave Applications: Lap Shear Strength and Z-Pinning Study

Large composite structures manufactured out-of-autoclave require the assembly and bonding of multiple parts. A one-shot cure manufacturing method is demonstrated using powder epoxy. Lap shear plates were from epoxy glass fiber-reinforced plastic with four different cases assessed: secondary standard adhesive film, epoxy, co-curing, co-curing plus a novel Z-pinning method. This work investigates lap strength in accordance ISO 4587:2003. Damage mechanisms fracture behavior explored digital image correlation (DIC) scanning electron microscopy (SEM), respectively. VTFA400 had load at break 24.8% lower than Co-curing increased by 7.8% compared to bonding, co-cured pinned joint resulting 45.4% increase. In cases, DIC indicated premature failure due resin spew. SEM areas large amount fiber pullout both these pinning delaying phenomena strength. highlights potential for out-of-autoclave.