Through-thickness strength measurements using Arcan’s method

This paper presents results obtained from the experimental study on the behaviour of glass/epoxy butterfly-shaped specimens tested under pure shear and biaxial loadings using an Arcan device. Notch-to-notch longitudinally and perpendicularly oriented fibre specimens, respectively referred to as Mat31 and Mat32 ones have been tested with different loading angles ranging from 0° to 90°. The fracture mode was more or less repetitive for Mat31 specimens whereas it depended on the loading direction for Mat32 type, for which the number of cracks and the obliqueness relative to the notch-to-notch line, decreased as the test angle increased. The comparison of failure envelopes has demonstrated that Mat31 specimens are much more resistant whatever the loading angle. However, strengths at failure of Mat32 type are in good agreement with Hashin’s failure criterion, for pure shear tests up to 30° loading angles. Mat31 specimens’ failure stresses were overestimated by the criterion, although similarities in trends were noticed.