Fatigue and fatigue after impact behaviour of Thin- and Thick-Ply composites observed by computed tomography

This study investigates the influence of load ratio and impact damage on fatigue behaviour high-performance carbon fibre reinforced polymers (CFRP) with areal weights between 30 gsm 360 gsm. For undamaged samples, ultimate tensile compressive strength, as well properties, are evaluated regard to their layer thicknesses. The tests were performed under tension-tension (R=0.1), tension-compression (R=-0.5) compression-compression (R=10) regime. results illustrated a constant-life diagram, piecewise linear interpolation examines first prediction. show that static performance improves decreasing thickness. Particularly loading, significant improvements observed, due suppression matrix cracks delaminations thinner layers. In addition, effect low-energy Thin- Thick-Ply laminates is investigated. demonstrate although delamination area larger, Thin-Ply can sustain higher stresses still reach same number cycles in contrast laminates. Computed tomography measurements visualize 3-dimensional progression after various prove composites no increase damaged during fatigue. interlaminar stress at not sufficient for expansion. contrast, case thicker layers, growths progressively throughout whole sample increasing cycles.