Load Amplitude Confounds Cycle-Resolved Damping in Displacement-Controlled Flexural-Tensile Fatigue of Unidirectional CFRP

<p dir="ltr">Cycle-resolved hysteresis-loop measurements from 57 unidirectional carbon fibre-reinforced polymer (CFRP) coupons tested in displacement-controlled, fully reversed four-point bending, together with the derived analysis tables, the analysis code and the publication figures.</p><p dir="ltr">The dataset contains 78,189 cycle-resolved load–displacement records. One complete load–displacement cycle was recorded every 1,000 cycles — every 5,000 for one coupon — at 125 samples per cycle (100 for two coupons), at 4 Hz and R = −1, where R is the ratio of minimum to maximum crosshead displacement and not a stress ratio.

Three nominal fibre volume fractions (40, 50 and 60 %) and four crosshead displacement amplitudes (3, 5, 7 and 9 mm) were tested, five coupons planned per condition, and records were recovered for 57 of the 60.</p><p dir="ltr"><b>Scope of reproduction.</b> The specimen-level estimates and their pooling, the multilevel models, the session treatments and the aggregation-level comparison are reproducible from the deposited cycle-resolved records alone.