Fatigue behavior and self-heating mechanism of novel glass fiber reinforced thermoplastic composite

In this study, fatigue properties of a novel continuous glass fiber reinforced composite with an acrylic-based thermoplastic matrix Elium®, have been investigated and S-N curves were obtained. The effect of various fiber orientations of the plies with glass fibers of 0°/90°/±45°, 0°/90°, and ±45° alignment has been evaluated. The highest fatigue strengths have been recorded for composites with 0°/90° glass fiber ply orientations. Composite with ±45° alignment has the lowest fatigue strengths in S-N curves. Stiffness degradation of the composites with 0°/90° and 0°/90°/±45° at medium fatigue stress levels was calculated and showed higher degradation for stacking having more off-axis plies, i.e. 0°/90°/±45° alignment. Temperature increase during fatigue testing was measured using an IR camera for a medium fatigue stress level for 0°/90°/±45° alignment. Temperature increases were calculated for all stress amplitudes for composites with 0°/90°/±45° and 0°/90° alignment cross-ply sequences. The temperatures obtained were all below the glass transition temperature of the material. The 0°/90°/±45° plies had a higher temperature effect than 0°/90° plies in both analytical calculations and observations.