Determination of fiber/matrix adhesion using the Outwater–Murphy single fiber specimen

Fiber/matrix (F/M) interface toughness values of carbon/vinylester 411 and glass/vinylester 411 has been determined using the Outwater–Murphy (OM) single-fiber compression test specimen. The OM test specimen consists of a rectangular block of matrix with a centrally embedded fiber with a hole drilled through the specimen and the fiber. Upon loading of the specimen in compression, the fiber may debond at the hole edge. The interface toughness can be determined from the measured values of the critical load for debonding. The fiber/matrix debond toughness values for dry carbon/vinylester and glass/vinylester were 51.2 and 38 J/m2, respectively, in reasonable agreement with previously published data determined using other test methods. Testing of water immersed carbon/vinylester 411 and glass/vinylester 411 OM specimens revealed significant reductions of the fiber/matrix adhesion.