• Tabrizi, Isa Emami
• Yildirim, C.
• Yildiz, M.
• Al-Nadhari, A.
• Beylergil, B.
• Topal, S.

Abstract

The failure behavior of carbon fiber/poly(ether ketone ketone) (CF/PEKK) composites manufactured via automated fiber placement (AFP) followed by subsequent consolidation in autoclave is studied. Multi-instrumental structural health monitoring (SHM) approaches are used to analyze damagedevelopment stages and and damage typesin high performance thermoplastic composite laminates. Void analysis, and density measurement, and optical microscopy reveal the effect of secondary consolidation through autoclave on the microstructure of the composite laminates. An interlaminar void reduction from 5.65% to 0.46% are observed. Acoustic emission (AE), digital image correlation (DIC), andinfrared thermography (IRT) techniques during tensile tests provide complementary understanding of the physics behind the critical damage types occurring in the material, such as edge splitting. Slope of the cumulative AE counts and percentage of total number of hits signify two distinct stages of failure, each associated with a dominant failure mode. Also it is evident that the high energy AE hits arecorresponding to macro level damage events which are captured by the IRT in the form of various edge splitting. The initiation of these damage events can be anticipated through concurrent monitoring of DIC strain maps.

Topics

• density
• impedance spectroscopy
• microstructure
• Carbon
• composite
• acoustic emission
• void
• optical microscopy
• thermoplastic
• ketone
• thermography