DUAL RESIN BONDED JOINTS IN POLYETHERETHERKETONE (PEEK) MATRIX COMPOSITES

The joining of thermoplastic matrix composite subassemblies into struc tures using traditional bonding approaches presents a number of techni cal difficulties leading to high fabrication costs and low performance . In an attempt to alleviate these problems this study examines the me chanical performance of structures assembled using a dual resin (misci ble polymer) bonding technique. This study focuses on joints between t hin walled square tubes, formed from carbon fiber/PEEK (APC-2) prepreg tape, and half cruciform joints woven from commingled AS4 carbon fibe r/PEEK yarn. The carbon fiber/PEEK joints are assembled using Polyethe rimide (PEI) as the bonding polymer. Prototype hand held hardware was designed for the application of the necessary temperature and pressure to the joint. Tensile tests on the half cruciform/tube subassemblies give information on the shear strength of the tube/cruciform joints an d on the practicality of producing such joints in an in-service enviro nment. Testing was performed at temperatures of -150-degrees-C, 20-deg rees-C, and +150-degrees-C, yielding trends related to temperature for the maximum strength and stiffness of the double lap shear bonds.