Characterization and Simulation of the Interface between a Continuous and Discontinuous Carbon Fiber Reinforced Thermoplastic by Using the Climbing Drum Peel Test Considering Humidity

The objective of this paper is to investigate the debonding behavior of the interface between
continuously and discontinuously fiber reinforced thermoplastics using the climbing drum peel test.
The study emphasizes on the importance of considering different climatic boundary conditions on
the properties of thermoplastics. Specimens with varying moisture contents, from 0 m.% up to above
6 m.% are prepared and tested. It is observed that an increase in moisture content from 0 m.% to 2 m.%
results in an increase of the fracture surface energy from 1.07 · 103 J / m2 to 2.40 · 103 J / m2 required
to separate the two materials, but a further increase in moisture to 6.35 m.% conversely results in a
subsequent decrease of the required energy to 1.91 · 103 J / m2. The study presents an explanatory
model of increasing plasticization of the polymer due to increased polymer chain mobility, which
results in more deformation energy being required to propagate the crack, which is corroborated
in SEM investigations of the fracture surface. A further increase in humidity leads to polymer
degradation due to hydrolysis, which explains the subsequent reduction of the fracture energy. ... mehrThe
experimental set up is modeled numerically for the first time with cohesive surfaces, which could
successfully reproduce the effective force-displacement curve in the experiment by varying the
interface parameters in the model over an influence length, allowing the conclusion of a process
induced variation in the interface properties over a specific consolidation length.