New publication: critical evaluation of torsion rheometry to characterize anisotropic intraply shear resistance

PhD researcher Dennis Brands recently published a paper titled "Critical evaluation of torsion rheometry to characterize the anisotropic intraply shear resistance of unidirectional thermoplastic composites in melt".

In the research, small-strain oscillatory torsion tests were analyzed using a linear viscoelastic model. The results showed good agreement with the initial slope of the torque rotation curve obtained from transient torsion tests. However, the limited strain range restricts applicability to small deformations. For larger strains, transient torsion tests revealed anisotropic and inhomogeneous behavior, with significant through thickness shear instead of the desired in-plane shear. This contradicted the transverse isotropy assumption originally used in modeling. To address this a nonlinear anisotropic viscoelastic model was introduced, offering improved accuracy. Still the inability to accurately control or monitor deformation during testing raised concerns about the reliability of transient torsion rheometry for characterizing in-plane shear behavior.

This paper was published in the Composites Part A: Applied Science and Manufacturing journal and performed in collaboration with Sebastiaan Haanappel, Wouter Grouve, Sebastiaan Wijskamp, and Remko Akkerman. The work is part of the research program ‘‘MaterialenNL’’ , which is (partly) financed by the Dutch Research Council (NWO).

Check out other publications on thermoplastic composites here.