Postbuckling failure behaviors and strength were investigated in compression tests of the hat stiffened composite panels manufactured with different bonding methods and different stiffener section shapes. The skin-stiffener separation loads, separation failure behaviors and final collapse loads were different with respect to bonding methods and stiffener shapes. As the separation failure was initiated early and propagated larger area, collapse loads and structural performance of the panels decreased. The test results showed that the co-curing with or without adhesive film and open type stiffeners were most beneficial for the postbuckling strength.

No abstract