... s , at negative stress ratios ( R ) , R = − 1 , − 0.75 , − 0.5 , − 0.25 , 0. The [ ± 45 ° ] 2 s specimens were found to have higher fatigue strength than the [ 0 , 90 ° ] 2 s specimens at all stress ratios. This is attributed to the difference in local stress components, the [ ± 45 ° ] 2 s specimens...

...M. Nasr; M. N. Abouelwafa; A. Gomaa; A. Hamdy; E. Morsi Thin-walled tubular specimens, made from woven-roving glass fiber-reinforced polyester (GFRP) with two fiber orientations, [ ± 45 ° ] 2 s and [ 0 , 90 ° ] 2 s , were tested under torsional fatigue tests at negative stress ratios R , R = − 1...